With cross server persistence in DayZ, (The location where you leave a game is where you will start when you resume play) I don't see an easy way for a group of friends to join a server and start playing together from the jump. Even respawns are at random spots. The best you can do is to all join the same server and meet up at an agreed upon location. Given the size of this map and the lack of useable vehicles, that could take awhile.

Here is a link to the mod map if you don't already have it:
http://avidblur.com/arma2/