If you want! Life's a game anyways. Why not throw out the $15 for a monthly play and see if you like it! Can't hurt.
As far as character selection goes, it has to appeal to your STYLE of play. In theory, I'd love to play a warlock. I loved playing a necromancer in Diablo 2, the curses and the minions - sitting back on the sidelines and letting the war in front of me work itself out while the enemies iron maidened themselves to death! However, I HATED playing a warlock. I hate the individual curses, I hate having pets, I hate the feel of the class.
In WoW, I found that my favorite class to play is a Druid Healer. The dynamic heal-over-times and the instant casts and the flurry of green numbers splurting from all the people is just so fun to me for some reason.
I loved playing a Protection Paladin back when I could solo a shitload of mobs with no real problem. Those days are gone though! I had to convert to a shockadin, which is so silly that it's awesome and it does pretty damn good DPS at 55 (its current level). Plus, there's nothing more amusing to me when I'm doing competative DPS in a random dungeon and the other players go "Holy DPS wtf lol!!"
HOLY LIGHT JUDGEMENT EXORCISM EXORCISM EXORCISM EXORCISM x 100
DDDDD
If you DO roll a healer, make sure to get Healbot. It makes life SO much easier.