I'll give you a quick rundown if you'd like, Blythe.
First off, all of the classes can solo, especially once you get your free companion at 16. When you get to the upper levels, the basic free companion starts to lag behind, but for a long while they are very helpful.
The Trickster Rogue is a lot like rogues in other MMOs. Great burst damage to single targets. It works a bit differently though in a few ways, not the least of which is that you have limited stealth. When you unlock stealth (at level 10), when you activate it you have about 5 seconds of stealth, in which you have combat advantage. More damage, higher crits, all that. Using any powers but your at-will/autoattack ones use up some of that time, as does taking damage (from an AOE or the like). You can spec for more stealth time, though, and you have tricks to help refill the bar faster. And they look cool with all the stabbing.
Devoted Cleric is the best solo class in my opinion. If you don't care to group much until the higher levels, the Devoted Cleric has it easy. Lots of different heals, solid damage, can easily be specc'd to DPS or to full heal, or somewhere in between. Again, a bit different from other healer MMO classes, though. Much more bent towards healing attacks, heal over times, and the like, with a bit of control put in for fun. At 10 unlocks the Divine Power bar, which fills as you do damage, and can be activated with tab to add extra power to your encounter powers. Changes your at will powers to a channeled direct damage, or a channeled direct heal.
Control Wizard is not what you would expect, if you are used to WoW and the like. Most of the CW's control is in interrupts and debuffs. You can extend the duration of their control through speccing, but these guys are much more Direct Damage/Control. You will move around a lot with them, temporarily freeze enemies, and do a lot of direct and aoe damage. Like the other classes, at 10 you unlock Arcane Mastery, which you build with your at will attacks, and adds power/extra effects to your encounter and daily powers.
Guardian Fighters are tanks, pure and simple. They snap aggro, the generate aggro, and they do it well. Can be specc'd to DPS surprisingly well, though, and they have decent AOE abilities. Honestly, they are pretty much like a tank from any other MMO. Good for soloing, too.
Great weapon fighters are DPS/AOE melee strikers. They hit hard, they can clear trash mobs well, and they can make decent off tanks/backup tanks. Currently they are considered a little bit of a gimp class, but I've seen a lot of builds emerging that make them very viable in groups and solo.
Just a few class observations from me, given that I've tried them all. (Cleric is still my fave).
When you unlock professions (around lvl 10 or 11, if I recall), for anyone who doesn't plan to spend money on the game, I would suggest looking into leadership first. You'll outlevel the equipment you can make with the other professions fast, while Leadership will net you xp, money, tradeskill goods, and Astral Diamonds, which can be traded for Zen (the pay-real-money-for currency) to buy things from the Zen store.