Wow,
Gray Lensman, I feel for you! Everybody has had a thread hijacked at some point or other, but this being your first... sorry, mate.
Some points on character competency and build power, for what it's worth:
You've done things in the right order, IMHO. You've come up with a character concept and back story, then you looked into translating this concept into a mechanical representation. This mechanical representation (recorded on your 'character sheet') should not be confused with your character (in your mind), and you seem to know this already, so I'll not delve into the distinction more than necessary.
When coming up with a mechanical representation of your character concept, you can go one of two paths: a) disconnect the mechanical side from the conceptual, or b) try and harmonize the two as much as possible. These are polar opposites, and most of the time your approach will fall somewhere in between. Most people will argue that b) should be your goal at all times, and straying near a) constitutes a gamer sin in some way. However, a) will not be possible to avoid completely, this being an abstract rules system etc. Also, see the following.
D&D as a game system assumes a high level of combat/conflict. Your character's mechanical representation (your build, in short) can be more or less competent at whatever his role in a given conflict will likely be. The level of your build's competency will thus be tied into how you envision your character: competent, or less so? Your opening post seems to indicate that you want your character to be competent at what she does, so you best optimize your build a bit if you want a character concept that is in harmony with your back story.
There's absolutely nothing wrong with this, don't let anybody talk you out of this. I've built mages confident in their ability to ensure success as well as strategically inept mages, I've played a warrior who longed to be a poet (but was bad at swordfighting AND poetry), I've played characters who were competent but didn't realize it, I've played characters who were incompetent but didn't realize it... competency is just one side of a character's personality.
That being said, D&D does revolve around killing things and taking their stuff a lot of the time - depending on your group's playstyle, of course. Also, being a hero, even just a regular adventurer, demands that your character perform a cut above the average Joe the Plumber where heroic, adventury activities are concerned. For this reason, aiming for competency in a D&D character is often considered a given. From which follows: many people tend to like powerful builds.
What kind of power your build can achieve depends not only on your optimization skills, but also on your willingness to stray towards option a) (see above) in some measure. Maybe a Guisarme and Armor Spikes are not how you envisioned your
character's equipmentin the first place... but it's also mechanically useful for your
build. Maybe taking Barbarian first, Rogue second is a necessity given your back story - but the other way round, you'd gain so many juicy skillpoints...
Nobody can tell you how far to go with this kind of disconnect. This is for you to decide. Note that you can adapt your back story to your mechanical needs - again, it's up to you to decide whether you want to do that. This will probably make you more of a powergamer. However, that doesn't mean you're going to hell, either. You need to realize that adapting your character concept to what you like mechanically doesn't make your character any less your own. It may make you feel like you sold out a character for a build, though. And that's not how I (or many other people) would define roleplaying. As always, do what works for you.
That being said (and sorry for the wall of text), it seems to me you'd like mechanical advice first and foremost. This makes sense to me (as does the fact that a lot of the internet discussions are about 'crunch' not 'fluff'), since your character is your own to create, but people can and will be of help where the translation into game mechanics is concerned.
Building Keera's mechanical representation:
You want Keera to be competent at fighting, as well as being generally outdoors-y. Mechanically, this calls for good attack bonus and weapon proficiencies, ability scores that allow you to fight well, a bunch of skillpoints plus wilderness skills as class skills, and maybe something like an animal companion, supernatural abilities or spells to do with the wilderness, wildshape etc. That's all. How you achieve these goals is up to you.
There's no need to take a specific class, much less stick to it throughout your career, because that class somehow furthers your character concept. Sure, a single-classed Ranger can achieve all of the above. But so can a Druid/Barbarian/Fighter/Rogue/Scout/Duskblade/Crusader/Ranger, with the right selection of skills, spells, feats, maneuvers etc. Look at what you want mechanically, and where you can get it. Waste not a thought on flavorful descriptions of class features, feats and so on. You've got all the flavor you want in your head: that's your character concept. As long as we're talking builds, don't get sentimental.
Here, in rough order, is how you might go about building your PC, based on simple assumptions:
Combat Style:
Generally speaking, two-handed combat is the best melee fighting style (as opposed to one-handed, sword-and-board, or two-weapon fighting). Archery is the best ranged style (as opposed to crossbows and throwing weapons).
Weapons:
The best two-handed weapons, apart from base damage and crit, allow/give bonuses to combat maneuvers like tripping and disarming, and/or have reach. This is why the Spiked Chain is the best weapon in the game - unfortunately, it costs a feat, being an exotic weapon. A Guisarme is almost as good and only takes martial proficiency. Armor Spikes go well with a Guisarme because they allow you to threaten the area immediately surrounding you. The best bow is a Composite Longbow matching your strength.
Feats:
Power Attack is the basis for dealing great amounts of melee damage. It also opens the way to Cleave, or Improved Bullrush-->Shock Trooper, or Improved Sunder-->Combat Brute. Going not only for HP damage, but also for combat maneuvers, you'd best pick up Improved Trip, which necessitates Combat Expertise. Using a reach weapon to control the battlefield around you makes Combat Reflexes attractive (keep in mind you need good Dex for this). You might or might not want Exotic Weapon Proficiency for the Spiked Chain.
Archery needs (or at least makes attractive) the following feats: Point Blank Shot, Precise Shot and Improved Precise Shot, Rapid Shot, maybe Manyshot and Greater Manyshot, maybe Far Shot, Woodland Archer, Penetrating Shot.
There's so few pure utility feats out there (aside from Track, which you can pick up with a level of Ranger) that I'll not go into those.
Decision time, since you can only do so much: what will your focus in combat be, melee or ranged? If melee, damage or battlefield control? If ranged, which of the many feats available?
Class features:
Many classes offer bonus feats to fill your above needs. That's not what interests us here, though. First of all, decide whether and how much supernatural stuff you want to have going on. Note that magic>>>mundane almost all the time in D&D. Spellcasting is the 'best' ability you can get mechanically, as it allows for great flexibility and power. If you want spellcasting, how much of it?
You've already stated you wanted a main combatant, which usually doesn't go too well with full casting - although a Cleric (ab-)using Divine Power and similar buffs can fight with the best of them, and a Druid can wildshape into a Dire Bear so he can flank with this Dire Tiger animal companion. So there ARE ways of going full caster and still being a melee or ranged combat threat.
The Ranger offers a little bit of spellcasting to supplement your outdoors-y style. The Scout doesn't, but it has lots of mundane outdoors-y stuff going on that can almost match a Ranger's casting. The Druid (and Wildshape Ranger variant) can turn into animals, which is kinda cool. So I ask again: how much supernatural-ness do you want?
There's a plethora of combat-related class features out there for you, from Favored Enemy to Uncanny Dodge to Sneak Attack to Rage to Fast Movement to Skirmish to friggin' Maneuvers and Stances. Pick the one(s) you want most.
Do you want a pet? A pet that can rip a Bugbear Shaman's face off? There's Animal Companions and Special Mounts (or, to a lesser degree, familiars) which can do that. Decide whether you want a pet.
Skills:
Basically, you can treat number of skill points and quality of class skills like just another class feature. I trust you won't pick only skill-less classes for your outdoors-y build, or you'll not be very competent in non-combat wilderness situations...
Synergy:
This is the hard part: figuring out how to fit it all together. This is where you should decide on your role(s), in and out of combat. Time to figure out what you want to be best at, what will be your secondary focus, etc. Then it's research, research, research, until you have the 'best' feats, spells, equipment etc. for what you want to do.
Once you are at this stage, the internet will be able to help you out well.
Class selection is the most important bit here. Keera might be represented as a single-classed Ranger using a Guisarme with Power Attack - mechanically bland, but will do the job of representing your concept. But maybe you'll go Ranger 1/Barbarian 1 (Lion Totem variant [Complete Champion]/Scout 4/Ranger 2-15 instead, with Swift Hunter, Improved Skirmish, and charge-related feats for wilderness character that can instakill anything she pounces upon unawares. Or maybe Ranger 2/Barbarian 2/Fighter 2/Bear Warrior 1/Warshaper 5/Bear Warrior 2-9 for a more mystical wilderness warrior who can turn into a freakin' BEAR and bite your face off. Or maybe Rogue 4/Swashbuckler 16 with the Daring Outlaw feat and some cross-class ranks in Survival for a sneaksy stalker who's good in any environment she can hide in, and will slit your throat before you notice she's there? Up to you.
Was this too basic? I hope not. If you have more specific questions, I'd be glad to answer them to the best of my ability. I just thought a really lengthy post might be the thing to break up the debate that has been plaguing this thread for so long...
Wasn't too bad, was actually a couple of interesting points made
