Crafting d20 NPCs from scratch can be a fun and satisfying activity, but it's almost never quick or simple. Fortunately for harried DMs, a few years ago the designers over at the Game Mechanics provided an extremely helpful method for developing stat blocks. Their system uses a template that guides the DM through the complex NPC creation process.
Fast forward a couple of years. Wizards of the Coast develops a new stat block format for the Dungeon Master's Guide II that greatly improves on the old one by using better organization and presentation of information, making the stat blocks much easier to use in the middle of a game session. (The new stat block format, with the addition of lines for Environment, Organization, Advancement, and Level Adjustment, also doubles as the new format for monster entries.)
The following template adopts the Game Mechanics method to the new stat block format. (You'll need to read the Game Mechanics article to get full use out of this tool.) Backup math goes into the red highlighted areas (I use a Word macro to clean these out for my final version). Brackets indicate optional blocks that are omitted if unnecessary.
One disadvantage of the new format is that the stat blocks tend to be a little longer than the old ones. I've provided a separate article with some suggestions on how to abbreviate these new stat blocks.
Gender race class XXlevel
AL Size creaturetype [(subtype)]
Init +XX (+XX Dex, misc. mods); Senses [special senses;] Listen +XX, Spot +XX
[Aura aura (range, DC XX)]
Languages languages
AC XX, touch XX, flat-footed XX (+XX armor, +XX Dex, +XX size, misc. mods)[; defenses][; AC feats]
hp XX (XX HD (+XX Race, +XX Class))[; fast healing XX][; DR XX/XX]
[Immune immunities]
[Resist resistances; SR XX]
Fort +XX, Ref +XX, Will +XX (Race F+XX, R+XX, W+XX; Class F+XX, R+XX, W+XX; Con +XX, Dex +XX, Wis +XX)[; save modifiers]
[Weakness XX]
Spd XX ft.[; speed feats]
Melee weapon +XX (damage) (+XX BAB, +XX Str, +XX size, +XX weapon quality, +XX feat)
Ranged weapon +XX (damage) (+XX BAB, +XX Dex, +XX size, +XX weapon quality, +XX feat)[; ranged atk feats]
[Space XX ft; Reach XX ft]
Base Atk +XX (+XX Race, +XX Class); Grp +XX
[Atk Options options; atk options feats]
[Special Actions special actions; special action feats]
Combat Gear gear
[Spells (CL XX, +XX melee touch, +XX ranged touch)]
[Spell-Like Abilities (CL XX)]
Abilities Str XX, Dex XX, Con XX, Int XX, Wis XX, Cha XX
[SQ special qualities]
Feats Feat XX level, Feat XX level, Feat XX level, Feat XX level
Skills Skill +XX, Skill +XX, Skill +XX, Skill +XX, Skill +XX
Possessions money derived from DMG tables for NPC wealth-item cost gp, item cost gp, item cost gp, item cost gp, item cost gp, XX gp remaining wealth in coins
[Spellbook All spells prepared plus XX]
[Hook hook]
[Ability (Type) description]
[Ability (Type) description]
Skills (class): Skill XX ranks (+XX ability score, +XX feat, +XX item, +XX racial trait), Skill XX ranks (+XX ability score, +XX feat, +XX item, +XX racial trait), Skill XX ranks (+XX ability score, +XX feat, +XX item, +XX racial trait), = XX (XX skill points)
NOTE: Number of feats is derived as follows: XX.