I have 3 friends that started playing Wow a couple of weeks ago.
They played FFXI previously, and they asked me a simmilar question.
Since thay have no want for a healing class, my advice to them was to level a druid to a decent level instead of leveling a bunch of other classes to a lower level because the power and abilities increases greatly farther you go.
This will allow you to test out 3 combat mechanincs,
Spell casting -> Mage, Ele shammy, Shadow Priest.
Kitty -> Energy and Combo point mechanics of Rogue
Bear -> Rage mechanics of Warriors.
They will have to go another route to test out DK, Pallies, Huntards and Enh. Shammy.
One really like Druid and stayed as Kitty, and the other 2 started a Rogue.
They also tried Pally and Huntard, but gave them up to focus on Rouge.
I wish I had this same advice when I was starting WoW. My first 3 toons were Hunt, War and Mage.
Started a Rogue for sh*ts and giggles and never looked back. Those 3 toons are still lvl 56, 34 and 33 respecively.
Hope this helps.
And yes....... Rogues are AMAZING.
Also, as the other poster stated, read up on what you are getting into and what is expected from you when playing any class that you choose.
Edited, Feb 3rd 2010 5:54pm by Krazman