Just to help out, these are the skill trees we currently know about:
DragonknightClass Tree 1: Unknown - Presumably based on melee offense
Class Tree 2: Unknown - Presumably based on defense/tanking
Class Tree 3: Unknown - Presumably based on spells/support effects
TemplarClass Tree 1: Unknown - Presumably based on Protection/Tanking
Class Tree 2: Unknown - Presumably based on Restoration/Healing
Class Tree 3: Unknown - Presumably based on Magic Damage
NightbladeClass Tree 1: Unknown - Presumably based on Melee Damage/Offense
Class Tree 2: Unknown - Presumably based on Archery / Ranged Damage
Class Tree 3: Unknown - Presumably based on magic, poison, and stealth bonuses
SorcerorClass Tree 1:
Dark Magic - Presumably based on Crowd Control and Defensive/Utility Magics
Class Tree 2:
Stormcalling - Presumably based on destruction and offensive magic / damage
Class Tree 3:
Daedric Summoning - Presumably based on conjuration magics and summoned support spells
WeaponsHand and Shield - 1h weapon + shield, probably involves more shield-focused attacks like bashing/charging
Two-handed - 2h weapons, probably focuses more on aoe/cleave type attacks
Dual Wield - Using two 1h weapons, probably based on heavy single target damage and fast attacks
Marksman - Ranged weapons (bows, and possibly crossbows), based on ranged damage, perhaps a mix of single target/aoe effects
Destruction Staff/Rune - Staff (2handed) or Rune (1 handed) weapons which emit magic for little to no cost, likely function similar to Marksman ranged attacks
Restoration Staff/Rune - Staff (2handed) or Rune (1 handed) weapons which will heal an allied target when used, for little to no cost.
ArmorLight Armor - Likely deals in cloth or padded armor types, and clothing. Probably focuses on giving bonuses to magicka and spellcasting.
Medium Armor - Likely deals in leather, studded, and scaled armor types. Probably focuses on giving bonuses to stamina and melee/ranged damage.
Heavy Armor - Likely deals in plate armor. Probably focuses on giving bonuses to health and protection/defense.
Special Skill TreesVampirism - Probably obtained by questline rather than being infected, we've heard that there will be a skill tree revolving around vampirism perks (probably involves draining life, stealth bonuses, and blood magic)
Lycanthropy - Similar to vampirism, no details yet
Mage's Guild - Rumored to provide at least one (maybe more) bonus skill trees for magic types not normally used by the classes
Fighter's Guild - It's not known if the fighters guild provides a skill tree, but we know the mages' guild does so it's safe to assume likewise
Dark Brotherhood - Similar predicament to the fighter's guild, and we dont know if it will be in at launch
Thieves Guild - Probably wont be in at launch from what we've heard