I am not aware adept handbooks. @HeyICanChan got the additional spells, though I'll note Lords of Madness does not actually list invoke the cerulean sign as an adept spell but specifically says "its magic is nearly universal and can be mastered by all spellcasting classes."
If you're willing to go 3.0 instead of 3.5, Masters of the Wild recommended the following spells be added to the adept list. I've listed the 3.5 sources for when I could fine them.
More Spells for Adepts sidebar, Masters of the Wild, p81 (DotF-Defenders of the Faith, MotW-Masters of the Wild, TaB-Tome and Blood):
0 - dawn (MotW) - SpC, p59
1 - hawkeye (MotW) - SpC, p110
1 - lesser cold orb (TaB) - SpC, p151, (orb of cold, lesser)
1 - scarecrow (MotW) -
2 - choke (TaB) -
2 - decomposition (MotW) - SpC, p61
2 - owl's wisdom (TaB) - PH, p259
3 - beastmask (DotF) -
3 - embrace the wild (MotW) - SpC, p79
3 - enhance familiar (TaB) - SpC, p82
4 - false bravado (MotW) -
4 - languor (MotW) - SpC, p130
4 - weather eye (DotF) - SpC, p238
5 - big sky (MotW) -
5 - ghostform (TaB) - SpC, p103
Here are the other alternate class features I've dug up for adepts from WotC sources:
Adept Alternate Class Features:
Familiar – Dragon 280, p60 - Alternative starting familiars. (3.0ED)
Familiar – Dragon 323, p88 - Specialist familiars. (3.5ED)
Familiar – Dragon 341, p96 - Specialist familiars. (3.5ED)
Familiar - Dragon 348, p88 - Unfamiliar territory: focus caster; (arcane reabsorbtion isn't valid as it specifically calls out arcane spells). (3.5ED)
Goblin of Grodd - Into the Dragon's Lair, p86 – An adept of Grodd can rebuke or command shadows as a cleric of the same level. (3.0ED)
Goblin of Grodd - Into the Dragon's Lair, p90-91 – Alternate spell list. (3.0ED)
Kobold - Races of the Dragon, p48 - Alternate spell list: Swap animal trance and daylight with lesser restoration and create food & water, respectively. (3.5ED)
More Spells for Adepts sidebar - Masters of the Wild, p81 - Additional spells from Defenders of the Faith, Masters of the Wild, Tome and Blood. (3.0ED)
Religious Adept – Eberron Campaign Setting, p256 – Add ability to choose a domain from the god worshipped; add domain spells to spell list and gain domain power, treating adept level as cleric level. (3.5ED)
Religious Urban Adept – Sharn: City of Towers, p167 – Alternate spell list, add ability to choose a domain from the god worshipped; add domain spells to spell list and gain domain power, treating adept level as cleric level. (3.5ED)
Urban Adept – Sharn: City of Towers, p167 – Alternate spell list. (3.5ED)