Questions about wow

[Mosqwik]

I am considering starting Wow but i have some questions to ask and i trut your judgement/guidance.


1)I dont really understand...

Do you pick a realm then make characters in that realm then decide on them if you are going to be pvp or pve or whatever else you cant be?? or do choose a realm then a playing thing (I mean pve or pvp) then all the characters you make have to play in there???

2) is it horde or alliance all the time??

I mean do you pick one then you are stuff in that group forever or can you make different characters in each ?

3) is it really worth the money ?

for me its like ?8 a month $15 atm i think cos of exchange rate. As well as the ?20 to actually buy it.

thanks