Credit to azgard12 at ps3trophies.com.this is just intended for a reference guide.

SKILLS
Q: When do I get Skill/Power Points?
A: You get Skill Points upon reaching an even numbered level and Power Points when reaching an odd numbered level. This means youll have 15 Skill Points at maximum level, which is more than enough to purchase skills for both roles and still pick up some unnecessary or frivolous skills.

Q: What should I spend my points on? I dont have enough points!
A: Remember that you only get to slot SIX skills at a time. Even with both roles using completely different moves (which, they usually wont) that still leaves you with three leftover skill points. Considering that most trees have a few worthless skills and that almost none of the iconic powers are worthwhile will leave you with a pretty clear path for what skills to choose. However, sometimes it is worth it to have a few of those extra abilities on hand to swap into your slots manually for certain fights.

Q: Which skills are worthwhile and which arent?
A: Since this is an MMO, skills are constantly changing. In Beta, Gadgets Tazer and Fires simple Fireball ruled the game, but theyve since changed. These are currently the best loadouts:


FIRE
Recommended Damage Loadout:
1) Fireball (or Meteor Strike*)
2) Detonate
3) Enflame (or Spontanous Combustion*)
4) Flame Cascade (or Wildfire*)
5) Mass Detonation
6) Reignition

Recommended Tank Loadout:
1) Fireball (or Meteor Strike*)
2) Absorb Heat
3) Backdraft (swap for Burnout in PvP)
4) Burning Determination (or Stoke Flames*)
5) Reignition
6) Eternal Flame

Obtaining this build will cost you 12 Power Points, leaving 3 available for other Powers or Iconic Powers. You could easily spend these on the optional powers with asterisks by them, but often the passive Iconic Powers will benefit you more, especially Nanoweave Armor.


ICE
Recommended Damage Loadout:
1) Inescapable Storm (or Cold Snap)
2) Frost Snipe
3) Freeze Wave (or Glacier Flash)
4) Avalanche
5) Ice Elemental
6) Freeze Ray (or Blizzard*)

Recommended Tank Loadout:
1) Cold Snap
2) Frost Snipe
3) Reflection
4) Shatter Restraints
5) Ice Elemental
6) Hibernation

Obtaining this build will cost 11 Power Points, leaving you with four to spend as you choose. It is highly recommended to put some of these points into the passive Iconic Powers, especially Nanoweave Armor.
Thanks to Bobbob.


MENTAL
Recommended Damage Loadout:
1) Psychic Blades (or Telekinesis)
2) Telekinetic Push
3) Telekinetic Bolt
4) Psychic Shock
5) Grandeur
6) Psychic Shield (or Bolt Barrage*)

Recommended Controller Loadout:
1) Telekinesis (or Psychic Blades)
2) Psychic Empowerment
3) Terrorize
4) Thought Bubble
5) Menace (swap Reflect Pain* or Horrific Visage* for PvP)
6) Psychic Shield

Obtaining this build will cost you 12 Power Points, leaving you with three points to spend as you choose. Mental has two really great PvP abilities that are unfortunately split at opposite ends of the Illusion Tree. Reflect Pain is likely to help you when youre on your own, but Horrific Visage will shut down enemy healing. If you look into Iconic Powers, Wisdom of Solomon is excellent, and Intimidating Gaze is also worth considering.


GADGETS
Recommended Damage Loadout:
1) Sticky Bomb (or Taser Pull)
2) Fear Gas
3) Gag Glove
4) Intimidation
5) Neural Neutralizer
6) Asphyxiation Gas

Recommended Controller Loadout:
1) Taser Pull
2) Defibrillator
3) Gag Glove
4) Bomb (or Cryo-Foam*)
5) Gauss Grenade
6) Anesthetic (or Stasis Field*)

Obtaining this build will cost you 11 Power Points, leaving you with four points to spend as you choose on other powers or Iconic Powers. Id highly recommend picking up the passive Iconic Powers Wisdom of Solomon and Intimidating Gaze. Also, there are two interesting moves that are missing from this build: Stealth (which is very fun to play with) and Hide (which can save your butt).


SORCERY
Recommended Damage Loadout:
1) Condemn
2) Shared Fate (or Final Ruin*)
3) Karmic Backlash
4) Rejuvenate
5) Boon of Souls
6) Polymorph (or Transcendance*)

Recommended Healing Loadout:
1) Rejuvenate
2) Invocation of Renewal
3) Boon of Souls
4) Circle of Protection
5) Polymorph (or Summon Watcher*)
6) Transcendance (or Arbiter of Destiny*)

Obtaining this build will cost you 10 Power Points, leaving you five to spend as you choose. You could easily spend these on the optional powers with asterisks by them, but often the passive Iconic Powers will benefit you more, especially Miracle Worker or Wisdom of Solomon (for the Power). Ive currently found the Summons to be very lackluster and unpredictably glitchy, so I do not rely on those. Also, power skills from Super-Speed seem to greatly help the Sorcerer, such as Whirling Dervish and Metabolic Boost.


NATURE
Recommended Damage Loadout:
1) Vine Lash
2) Briar
3) Roar
4) Rampage
5) Primal Wolf Form***
6) Pterosaur Form***

Recommended Healing Loadout:
1) Metabolism (or Hive Mind*)
2) Blossom
3) Bloom (or Cross Pollination*)
4) Thorn Shield
5) Regeneration
6) Insectoid Form***

Obtaining this build will cost you 12 Power Points, leaving you three to spend as you choose. You could easily spend these on the optional powers with asterisks by them and youll also likely be tempted to purchase all the different animal forms (and it isnt a bad idea). ***Remember that you have entirely different power sets as different forms.