How does Rift's class selection system work?
Solution 1:
I'll try to put them in ways you'll relate to :)
Souls are unlocked as you do quests and close rifts as you level up.
Each Calling (class) has access to 9 souls (talent trees).
You can pick any 3 souls at any given time (when you've earned them all) and can swap between up to 4 different soul settings (think dual spec but with 4 slots).
Recommendations are usually not suggested as an answer on these boards. But to give you a little direction, a hunter (which I also played :D) is in the rogue calling, and a shaman is more of a cleric calling.
Solution 2:
The game has four callings: Warrior, Rogue, Cleric and Mage; and and each calling has nine souls.
Essentially, the callings are your class. They determine the type of gear you are allowed to equip, the souls you have access to, as well as your stats.
The souls are essentially just your skill trees. You can have up to three, and you'll gather them by doing quests in the game. You'll unlock your first three by level 5, and others around level 13. Every time you level, you gain skill points (the amount you gain depends on the level) and you'll have 66 skill points at Level 50 (current level cap).
The only restriction in distributing your points is you can not have more points in a tree then your current level. So, if you had two classes at level 10, Ranger and Nightblade, and had 14 skill points - you could put 10 into Ranger and 4 into Nightblade, or 7 into each, et cetera. But you could not put 11 or more points into any one skill. You can reset your skill points from a skill trainer for a cost - exactly like WoW.
Also, souls determine your spells/abilities as well. You unlock spells/abilities as you put points into a soul - and you can upgrade them further at a skill trainer.
Finally, their are also roles. You start off with one, and can purchase four more with in-game currency. Each role is just a combination of any three souls (of your class), and you can switch between them at any time (so long as you are not in combat). This works just like the dual spec from World of Warcraft - it will allow you to have multiple builds for one character.
Solution 3:
I've only played through the free trial of RIFT but here's a brief overview with how it relates to WoW's talent system.
As you progress through the starting area, you will have the opportunity to try out 3 different souls. You gain the basic powers of each 3 souls simultaneously. As you level, you gain points to spend in any of your 3 currently active souls. You unlock soul-specific abilities as you spend more points in that tree.
The key difference from WoW is that you get a point at each level, and sometimes even 2 points. But you can only spend up to your level in any single soul tree. So for example at level 10, you may have 14 points (not sure exactly) - but no more than 10 in any one soul. This forces you to advance in at least two trees at once, and leads to many interesting combinations depending on the souls you choose.
For my trial I played a rogue. My main tree allowed me to dish out some serious melee damage, but I put those extra points into a ranged soul so I generate combo points (and do a little damage) as the mob was running toward me. Then I could use those combo points toward my main soul's finisher.