How Do you?

How do you actual go about forming a guild in guild wars? Can anyone help me with that.....
What is a guild hall for one and how do you get one?
I ask this cause i havent actually played the game and wish to know this stuff before i buy it , i have played the beta a few times and didnt know how to create a guild in there. If anyone could explain not only how to make a guild , what a guild hall is , but everything there is to possibly know about a guild it would help.

The Search buttin is a wonderful tool :P I'm more than positive this has been covered before, but I'll recap:

You can form guilds for an NPC in the game called a "Guild Registar" He's also the same individual you goto when you have enough to make a guild cape (price has changed from one beta to another, but it'll be anywhere between 100, and 1000 gold)

Guild Halls im not too sure about, but from what I've heard, you can either buy one (in lion's arch) or win a token to get one by doing the Hall of heros, which is a PvP arena type deal.

How many people do you need to start a guild?

only 1, but it is best to only start a guild if you have people you know join or know people who want to be in a guild that will share in acomplishing missions or GvG battles.

Now I have a couple more questions if yall could answer , and i dont think it warnted a new thread.
CAn a roleplaying char still participate in pvp?
And how do you get items from your roleplaying char on the custom pvp chars
Can pvp chars leave pvp areas if not how can they join guilds?.