Backgrounds and Deities
BackgroundsIn particular I would recommend backgrounds that help with skills. Backgrounds that add perception to your list of class skills will in particular be a good choice for any cleric with a high wisdom. Backgrounds that add athletics or endurance as skills for battle or balanced clerics are also good choices.
Some other useful ones are listed below, but these are setting/campaign dependent and several of them your DM may think are overpowered (I know I think some of them are). The bolded ones in particular are useful and can give you bonuses like a martial weapon proficiency, resistances, or let you use wisdom or strength to determine your starting hitpoints:
Forgotten Realms Background: From FRPH or Dragon 366, 376, or 371
Gritty Sergeant: Simple or Martial Weapon Proficiency, +1 to initiative.
Nobile Bred for War: Simple or Martial Weapon Proficiency, +1 to Diplomacy checks.
Officer Who Came Out of Retirement: History class skill. +1 to History and initiative checks.
Chessenta: +1 to rolls made with action point.
Tarmalune D376: +1 to speed until end of turn when you spend an action point. +2 bonus Diplomacy.
Auspicious Birth: Substitute highest ability score to determine initial hitpoints.
Born Under a Bad Sign: Substitute highest ability score to determine initial hitpoints.
Impiltur: Use wisdom score for your starting hit points
Akanul: Gain resitance to cold, fire, and thunder.
Arcane Student who Saw too Much: +1 bonus to saving throws to end daze, stun, immobilize, or restrain.
Calmishan: Resist 4 fire, +5 to endurance checks related to thirst
Crusading Zealot: +1 bonus to saving throws until you fail a saving throw.
Former Gladiator: It takes 4 failed death throws to kill you
Haunted Vetern: Encounter: Trigger (failed a fear saving throw) Effect: Reroll that saving throw
Imbuer: You can construct implements and wondrous items. Implement takes 2 days, wondrous takes 4 days. Item cost is the same as if in store.. You can cast
Monster Hunter: +2 to monster knowledge checks
Necromancer's Chattel: +2 bonus to fear saving throws
Restless Dead: +1 to damage against undead
Sarifal D376: Gain Terrain walk Earth/Forest/Ice/Swamp
Scorned Noble: +2 bonus saving throws when no allies are within 5 squares of you.
Touched by Darkness: +1 to save against ongoing necrotic effects.
Wandering Mercenary: It takes 4 failed death throws to kill you
Warsmith: You can create weapons and armor and can cast creation rituals.
Windrise Ports D376: You can multiclass twice. This is potentially very broken.
Picking a DeityThere are a few things to consider before picking your Deity. First off you need to consider role playing reasons and settings. Some DMs may be pretty flexible about what domains and CDs are avaiable for characters in home brew settings so if you use a homebrew setting you might be able to ignore the rest of this advice and just pick which one looks good. For many campaigns you are restircted to just a few gods, usually the good/unaligned ones. Also some DMs may allow you to worship a pantheon and to pick from multiple gods feats/domains and the rules do not explicitly forbid this and imply that you can serve a pantheon at several points. After you have done that you need to look at the mechanical choices and here is where it gets tricky. You can actually build a prefectly functional cleric who does not take any Deity/domain specific feats. But a lot of the domain and CD feats along with some of the paragon paths are pretty useful besides making your cleric feel more unique and they require you to worship specific dieties or specific types of deities. So if you want to focus on radiant damage for instance it is ok to pick what flavor or powers you want for your cleric to be and then work backwords from there.
Domains and Associated DeitiesAvandra: Change, Freedom, Luck
Bahamut: Hope, Justice, Protection
Corellon: Arcana, Skill, Wilderness
Erathis: Civilization, Creation, Justice
Ioun: Fate, Knowledge, Skill
Kord: Storm, Strength, War
Melora: Life, Sea, Wilderness
Moradin: Creation, Earth, Protection
Pelor: Hope, Life, Sun
The Raven Queen: Death, Fate, Winter
Sehanine: Love, Moon, Trickery
Asmodeus: Civilization, Tyranny
Bane: Skill, War
Gruumsh: Destruction, Strength
Lolth: Darkness, Trickery
Tharizdun: Destruction, Madness
Tiamat: Strife, Vengeance
Torog: Earth, Torment
Vecna: Knowledge, Undeath
Zehir: Darkness, Poison
Forgotten RealmsAmaunator: Civilization, justice, sun
Angharradh: Hope, protection
Bahamut: Justice, strength
Berronar: Truesilver Life, protection
Chauntea: Earth, hope, life
Corellon: Arcana, skill, wilderness
Garl Glittergold: Creation, trickery
Gond: Creation, knowledge
Ilmater: Freedom, hope
Kelemvor: Death, fate, justice
Mielikki: Freedom, wilderness
Moradin: Creation, earth, protection
Oghma: Knowledge, skill, trickery
Selûne: Arcana, change, moon
Sheela Peryroyl: Love, wilderness
Silvanus: Life, storm, wilderness
Sune: Love, skill, trickery
Tempus: Protection, strength, war
Torm: Civilization, justice,protection
Tymora: Change, luck
Waukeen: Civilization, knowledge
Asmodeus: Knowledge, torment,tyranny
Auril: Storm, winter
Bane: Civilization, tyranny, war
Beshaba: Fate, trickery
Cyric: Madness, strife, trickery
Ghaunadaur: Destruction, earth, madness
Gruumsh: Destruction, storm,strength
Lolth: Darkness, poison, strife
Loviatar: Torment, vengeance
Luthic: Earth, protection
Shar: Darkness, knowledge,undeath
Sseth: Arcana, darkness
Talona: Destruction, poison
Tiamat: Tyranny, vengeance
Umberlee: Sea, storm
Zehir: Darkness, poison
EberronThe Silver Flame: Hope, justice, protection
The Sovereign Host: Civilization, fate, knowledge
Arawai: Life, storm, wilderness
Aureon: Arcana, justice, knowledge
Balinor: Earth, strength, wilderness
Boldrei: Civilization, justice, protection
Dol Arrah: Hope, sun, war
Dol Dorn: Skill, strength, war
Kol Korran: Civilization, skill, trickery
Olladra: Change, freedom, luck
Onatar: Civilization, creation, strength
The Blood of Vol: Death, undeath
The Path of Light: Freedom, skill, sun
The Spirits of the Past: Protection, vengeance, war
The Undying Court: Fate, knowledge, undeath
The Dark Six: Destruction, wilderness
The Devourer: Destruction, sea, storm
The Fury: Madness, vengeance
The Keeper: Death, torment
The Mockery: Trickery, war
The Shadow: Arcana, darkness
The Traveler: Change, creation, trickery
Cults of the Dragon Below: Darkness, madness
Dragon #378 is the source for the FR and Eberron domains.