Working on a build for 3.5 Wizard?

[MonkeySage]

I'm thinking of building, specifically, a Sun Elf Generalist Wizard, not specialist- but focused on primarily support. A character that can pull out fireballs and lightning bolts if it's necessary, but prefers to rely on subtler spells. Transmutations, illusions, buffs, and debuffs, rather than pure direct damage. I'm creating this character for a campaign of which I am sharing the DMing load, and he's for use when I'm *not* in the hot seat.

He'll be joining a large party:
A half drow Wilder, a dwarven cleric, a "Wood Elf" (Kobold raised by wood elves) druid, a tiefling rogue, a human fighter, and a half orc paladin.

[MaxiDuRaritry]

What level are you starting, what level do you see yourself ending at, what sources are available, and what optimization level are you comfortable at?

Regardless, I'd suggest going with the spontaneous divination ACF (Complete Champion). Give up your 5th level feat and gain the ability to spontaneously cast divination spells. Great for spending your excess slots at the end of each day (as there are many ways to protect yourself from attack at night, and you can use scrolls and wands if needed, if something does happen), and you can use it to gain information on what you should be filling your slots with the next day. Furthermore, you are now a spontaneous caster, which has all sorts of benefits when qualifying for stuff.

Oh, and if you're co-DMing, you can use the ACF to justify having the right loadout, since you have an in-character reason for having a good idea what's coming up.

[MonkeySage]

Probably starting at level 3, though hard to say where it will end. I dream big though, and never plan a hard and fast "end point" to the campaigns I run. I'd love to eventually go for the Archmage PrC, though, if I make it to that point.

As for books, it's easier to mention that I'm avoiding Unearthed Arcana for this campaign and since it's loosely based on the Forgotten Realms setting (while being a homebrew setting), I'm including a bunch of Forgotten Realms specific content. I am allowing psionics (hence the Wilder), and ruling that spells and effects that work on dispelling/detecting/reading magic also work on psionics.

Other than that, I'm judging on a case by case basis, a "Run it by me first" kinda deal if they're using content from non-core sources.

[Particle_Man]

The magic of the land feat might be nice eventually. Heal your targets a bit whenever you buff them.

[MaxiDuRaritry]

Probably starting at level 3, though hard to say where it will end. I dream big though, and never plan a hard and fast "end point" to the campaigns I run. I'd love to eventually go for the Archmage PrC, though, if I make it to that point.

As for books, it's easier to mention that I'm avoiding Unearthed Arcana for this campaign and since it's loosely based on the Forgotten Realms setting (while being a homebrew setting), I'm including a bunch of Forgotten Realms specific content. I am allowing psionics (hence the Wilder), and ruling that spells and effects that work on dispelling/detecting/reading magic also work on psionics.

Other than that, I'm judging on a case by case basis, a "Run it by me first" kinda deal if they're using content from non-core sources.Since you've got a lot of muggles (and a paladin that probably might as well be, optimization level depending), how about focusing on buffs and debuffs, and working towards war weaver (Heroes of Battle)? Buff the party with your war weaver abilities, and then during each fight, focus on hindering enemies so the muggles can clean them up? After maxing out war weaver, legacy champion (with a custom legacy that doesn't suck) to keep progressing war weaver past its typical end-point, since it's fairly easy to extrapolate? You can always do archmage later on, if it's still a thing you want to do. You may also want to try working in some spellguard of Silverymoon, given your pseudo-FR campaign status and its ability to make personal-only spells usable by war weaver buffing.

(Also, Magic of the Land would make almost any spell usable via war weaver, if you take a few levels in spellguard.)

[Troacctid]

Elf wizard substitution levels from Races of the Wild are a must-have for any elven generalist.

If you're focusing primarily on support, it might be worth having Fiery Burst or Storm Bolt (both from Complete Mage) to give you a basic attack that you can use for offense without having to dedicate more than one slot to it.

Potentially interesting prestige classes off the top of my head: War Weaver from Heroes of Battle, Guild Wizard of Waterdeep from City of Splendors: Waterdeep, Urban Savant from Cityscape, Paragnostic Apostle and Squire of Legend from Complete Champion, and Olin Gisir from Lost Empires of Faerun.

[Biffoniacus_Furiou]

I'll agree that a reserve feat for dealing damage is going to be better than using spells for that. You shouldn't even need to deal damage considering you have a Rogue, Paladin, Fighter, and Druid in the party. Try to get the Raiment of the Four set pieces in MIC to spontaneously cast a Fireball if needed, without having to prepare it ahead of time.

Definitely get the Elf Wizard substitution levels in RotW, except maybe the 5th level which should probably be swapped for Spontaneous Divination in CC.

I'd aim for a War Weaver/Spellguard of Silverymoon build. A Sun Elf can be from Silverymoon, so aspiring to become a Spellguard is fitting. You could go Wizard 5/ War Weaver 5/ Spellguard of Silverymoon 5/ Archmage 5, but you'll be spending five of your six feats by level 15 to meet prerequisites. I'd personally skip Archmage, it's more suited to a specialist Wizard who takes Master Specialist levels, and/or an Initiate of the Sevenfold Veil, both of which have overlapping prerequisites with it.

For spell selections, at 1st level you've got Grease, Color Spray, and Wall of Smoke for attacking all three types of saves (Wall of Smoke can be cast across creatures' spaces to force an immediate save). At 2nd level you've got Web, Glitterdust, and Cloud of Bewilderment for the same purpose. At 3rd level there's Sleet Storm, Slow, and Stinking Cloud, to name a few. Pick up a 2nd level fire spell like Scorching Ray or Fireburst or Scorch or Molten Strike, etc. and learn Fiery Burst as your 3rd level feat. You'll need Enlarge Spell at 1st in this case to qualify for War Weaver on time, even though it's not going to do you any good for a while, but that's often the nature of prerequisites.

Pick up every knowledge skill and get the Collector of Stories skill trick in CS. It's also useful to pick up Magic Appraisal and Swift Concentration later on as well. On a notecard list each creature type (https://www.d20srd.org/srd/typesSubtypes.htm), the knowledge skill to identify it, what poor saves its racial HD grant, and any immunities every creature of that type always has. If your character can identify what its type is, your character should know those things about it and be able to pick the most appropriate spells to use (i.e. which saves to attack).

If you want to break the game, have everyone pitch in 2,000 gp for a 1st level Pearl of Power and to go in thirds on Lesser Rods of Extend. Give those to the Druid and have him use those to put Snowsight on everyone in the party. You, the Druid, and the Cleric can all cast Obscuring Snow and completely trounce every encounter that has enemies that are lacking blindsight, tremorsense, etc. Both of those spells are in Frostburn.

[Troacctid]

I'll agree that a reserve feat for dealing damage is going to be better than using spells for that. You shouldn't even need to deal damage considering you have a Rogue, Paladin, Fighter, and Druid in the party.
While it's true that it's not your main job to deal damage, it's also not always going to be optimal or necessary to use a spell slot every round, and when that's the case, reserve feats are an efficient use of your action—and the damage-dealing reserve feats tend to be head-and-shoulders above the non-damaging ones for this purpose. Also, rogues, paladins, and fighters all do their damage to only one enemy at a time; sometimes you need to sweep a lot of enemies off the board at once.

[Feldar]

Absolutely nothing beats war weaver in terms of support. One round, 26+ actions. To get this miraculous power? You give up one level of arcane spellcasting progression.

Win initiative, do your one thing, go get food while the rest of the group muddles through hours long slog of combat.