Corsair said:
1st level human warlock should get point blank and precise shot. After that, Mortalbane (BoVD) is a good choice (5/day extra 2d6 damage against non-outsider/non-construct/non-undead targets), along with Maximize and Quicken SLA.
I agree -- also usefull is Sudden Still Spell (which is explictly mentioned in the Complete Arcane as working with Warlock abilities) in case of a grapple -- Extra Invocation is nice too --
If you want to multiclass with anything with better armor proficiencys Amored caster (medium) and Armored caster (heavy) can be fun --
When it comes to race selection I like Human, Elf (if you have a real high con) Lightfoot Halfling (from FR they get an extra feat) or Warforged (from Ebberon) --
If you go the warforged route your feats should be (in this order) Mithril Body (you will be enchanting this later) Point Blank Shot, Precise Shot --
After that its up to you -- I recomend the following 9--Quicken Spell Like Ability 12 -- Maximize spell like ability 15-- Improved Toughness (don't laugh it gives mondo HP with your high con) and at 18 Extra Invocation
For other races Drop Mithril Body (obviously) and Improved Toughness -- you can sub Sudden Still (at 3) and an Extra Invocation (at 15) as well as something cool (Mortal Bane or Spell Penetration or something) if you are a human
Another odd possibility is an Elf -- If you have a high int and con (at least 14 with mod) Elf makes you into quite a "spotty" warlock -- take those feats from the Heros Handbook (Guerilla Scout and the otherone I forget) that lets you take Move Silent, Hide, Spot, Serach and Listen as class skills -- combine those with Darkness and Invisibility and you have a scout/warlock -- this requires a high Int though so unless your DM is like mine and gives all classes 2 extra SP it might be tricky -- Still the extra Dex helps your AC and you get a bonus to hit with your zaps and a nice sidearm for emergency melee -- longswords rule)
I don't recomend a multiclass Warlock but if I was going to do it I would go Human or Half Elf (or Shifter if you are doing Ebberon) and multi with Ranger for a scout type -- 1 level is all you really need -- The extra Skills (Move Silent and Hide) can be pretty nice as well as the Spot, Search and Listen for scouting --
The good things about such a combo is that the saves fill in your weak bits (Fort and Reflex) -- and the martial weapons are sweet -- You might FREX use a glaive and that melee blast shape -- The lack of Heavy Armor is no loss -- a warlock can't use it anyway with arcane failure or 2 more feats
Later if you like you can make yourself an Elven Cloak or Resistance and Eleven Boots of Striding and Springing and get the mobility feat tree i to be battlefield control Warlock
Other Combos I like include Swashbuckler/Warlock (just for fun) Mostly Ranger/A little Warlock for the Sneaky Detector guy (yes I have Darkvision, Can See Invisible and Detect Magic at will -- why do you ask ?) with the built in Zap
- Rogue/Warlock -- Scout/Warlock and that backstabby varient Thug from Unearthed Arcana --for choppy Warlock