Well... i played WoW for a long time...
I think it's one of the best Games, ever..
If u want to be good at this game, you have to volunteer a lot of time.
That sucks. But it makes a lot of fun.
1st you have to reach lvl 60/70, then search a succsessfull guild, to get nice items and master hard encounters.
The other oppurnitiy is doing PvP and get their new Items.
You will also find new friends, if you are honest to most of that players.
But remember, it takes a long time :S If you are a pupil and wants to be good at school, forget that game, if you're a student, buy it.
My advise to you, play the 1 month trial time, then decide to buy or not to buy.