Well....
Ability scores should prioritize Intelligence, Constitution, Dexterity, then Wisdom, in that order, with Charisma and Strength of minimal use to the wizard. You could do something a little different from that, but it wouldn't be very effective at some point; a high-Str wizard would be more effective at first, but whatever he gave up would be a pain around 5th-level or later.
To use a 32-point-buy example:
Str 8, Dex 16 (14+2 elf), Con 14 (16-2 elf), Int 16, Wis 14, Cha 8
or 25-point-buy:
Str 8, Dex 15 (13+2 elf), Con 14 (16-2 elf), Int 16, Wis 10, Cha 8
a bookish, snobbish/selfish/whatever elven mage who eats well and stays fit but only through simple exercises, with a too-high opinion of himself
You might at least save against a low-level trap, poison, stunning fist, or spell with these scores, but must expect to fail most Fortitude and Reflex saves. Stay at a good distance from the front of the group to avoid most traps, breath weapons, poisonous beasties, and such. Your hit points will be poor but at least good enough to survive a minor hit. Your Armor Class will at least be of some use, and decent enough when Mage Armor, Shield, and Alter Self are applied.
Your ability increase every 4 levels should go to Intelligence.
Feat-wise, go for Spell Focus and Greater Spell Focus in one or two schools of magic that you intend to use for offense or trapping foes, probably Conjuration or Evocation. Take Spell Penetration and Greater Spell Penetration once you reach the middle levels, like at 9th and 12th level. Besides this stuff, take Improved Initiative and maybe Lightning Reflexes/Great Fortitude to shore up your weak saves. Acting first or early in combat is important for a wizard.
Your wizardly bonus feats should probably be Item Creation feats and Metamagic feats; Craft Wand, Craft Magic Arms & Armor, or Craft Wondrous Item at 5th-level, maybe another of those at 10th-level, then Craft Staff or Forge Ring at 15th-level, and another of those at 20th-level. Quicken Spell should probably be thrown in at 10th-level, maybe 15th (it's worthless until 9th-level anyway, and most of its usefulness comes in around 13th or 15th). Scribe scrolls and craft wands or staves when needed to maintain a ready supply of any spell you really want to have available at any time, such as Magic Missile (for those pesky incorporeal foes that make warriors weep), See Invisibility, Dispel Magic, Knock, Fly, etc.
Skill-wise, invest a few ranks in several Knowledge skills, probably more ranks in Arcana and The Planes. Invest well in Spellcraft and Concentration, though your Concentration never really needs to go above a total bonus of +23 (it might help in very rare occasions to go above that, but hardly) for casting defensively. An elven wizard may have some ranks in a Craft skill as well, such as Craft (woodcarving), Craft (weaving), or Craft (weaponsmithing).
Eventually, you might want to multiclass into Archmage, as it is very fitting for an elven wizard and has some useful options.
As an elven wizard, you should start out with a longsword, and a light or heavy crossbow, and maybe a bit of acid or alchemist's fire. You don't have the Strength to make good use of bows, thus the crossbow.
Spell-wise, use Mage Armor often, but only after you have enough spell slots to spare (2nd or 3rd level onward). Use Shield whenever you suspect an enemy mage to be around or lots of enemies (to where you expect the warriors won't be able to protect you much). Once you have enough spell slots to spare, keep one Feather Fall prepared just in case. Your initial prepared spells might be Detect Magic, Disrupt Undead or Prestidigitation, Light, Burning Hands or Grease, and Magic Missile. Grease won't be much use early on, because of its very brief duration, but it could be handy if you toss alchemist's fire at a creature in the Greased area.
As a mage, you'll be expected to deal with incorporeal or other such nasty critters, and stuff like rust monsters or trolls, thus the need for Magic Missile/Disrupt Undead and other blasts occasionally. Since you're forgoing Enchantment and Illusion, you won't have access to the standard-issue Sleep/Color Spray choices that most mages use at low levels. Most of your attacks will be with sword and crossbow at low levels, until you get enough spells to actually do more-useful things all the time.
Remember that specialist wizards must learn at least one spell of their chosen school at each level that they learn new wizard spells. So you should probably start with just Magic Missile or Burning Hands, not both, then learn the other one at 2nd-level, then Scorching Ray or Shatter at 3rd-level, then something else at 4th, Fireball or Lightning Bolt at 5th, Gust of Wind or something at 6th, etc. Considering your elven wizard, Darkness might actually be of some use, turning the area around your enemies into shadowy conditions so that their eyesight is hindered, while your elven Low-Light Vision helps you to see further through the shadows so as to shoot or blast them. Still, generally speaking, Darkness or Daylight would not be good choices.
Ice Storm is not very good in my experience, so avoid it; Fire Shield, Shout, Resilient Sphere, or Wall of Ice would be better 4th-level spell choices. The latter two can provide some useful battlefield control, but you only need one; so take one of those and one of the others. Cone of Cold and Wall of Force are good 5th-level spells, but Sending might be quite handy in some campaigns instead of Cone of Cold, but usually CoC may be a better choice (lots of fire monsters and lots of cold monsters around....). Chain Lightning and Contingency will serve you well for 6th-level spells, though CL won't always be useful. Forcecage is probably a must for 7th-level, with Grasping Hand or Prismatic Spray secondary. Greater Shout and Telekinetic Sphere should be good 8th-level evocations.
As for non-evocations; good choices include Mage Armor, Shield, Feather Fall, Identify, Enlarge Person, See Invisibility, Web, Acid Arrow, Alter Self (troglodyte form will give a nice AC bonus, for example), Knock, Dispel Magic, Fly, Haste, Protection from Energy, Stoneskin, Polymorph, Scrying, Enervation, Dimensional Anchor, Lesser Globe of Invulnerability, Stone Shape, Break Enchantment, Teleport, Wall of Stone, Telepathic Bond, Baleful Polymorph, Transmute Rock to Mud (devastating underground or on mountains for mudslides/collapsing ceilings), Permanency, Globe of Invulnerability, Greater Dispel Magic, Analyze Dweomer, True Seeing, Disintegrate, Flesh to Stone, Spell Turning, Greater Teleport, Greater Arcane Sight, Reverse Gravity, Limited Wish, Dimensional Lock, Mind Blank, Trap the Soul, Discern Location, Moment of Prescience, Clone, Polymorph Any Object, Mage's Disjunction, Shapechange, Time Stop, and Wish.
Overall, though, Evocation isn't a very good choice of specialty, though it has its moments. Conjuration and Transmutation are generally better specialties, though they've got some bad levels too.
Item-wise, get the best Headband of Intellect you can find whenever you can; you'll eventually want a +6 Headband of Intellect. An Amulet of Health is probably the second-most-important, and Gloves of Dexterity third-most-important. A Cloak of Resistance should be acquired early and upgraded or replaced often until you have a +5 version. All of this will make your saving throws and HP less fragile, and the Int bonus will make your spells harder to resist and such.
Pearls of Power will serve you well. A Ring of Counterspells is a must; as soon as you get one, start using it to store Dispel Magic; you DO NOT want anyone dispelling your precious defenses (or flying/water breathing) at a critical moment. A Ring of Protection or Ring of Evasion may be handy as your second ring. It might behoove you to eventually acquire a Dagger or Quarterstaff +X of Defending, so as to gain an AC bonus from it at all times. Or it might not be worth it.
Bracers of Armor can be very handy, but only when their bonus is at least moderately higher than +4; until then, just rely on Mage Armor and such. Boots of Teleportation can be VERY handy indeed, but they're expensive, so before that you might just acquire Boots of Speed or Boots of Striding and Springing so as to more easily maneuver and escape enemies. A Portable Hole, Bag of Holding, or Handy Haversack is a must for any adventurer, at some point or another.
A Blessed Book will serve you well; scribing spells into it is free, and it has a thousand pages, which will save you a lot of money in the long run if you plan to learn more than just the 2 free spells per wizard level after 1st. Carry at least a few cheap healing potions for emergencies; with you at the back of the group, you might be the only survivor of a big blast or something, and might need to heal the cleric back to consciousness. One dose of Stone Salve can be handy, though it is expensive; you might need to de-petrify the cleric at some point.
