how do i create php user sessions?

[wapfuture]

helllo mates

ive been reading hundreds of tutorials on php sessions.. but none that have any good help.

ive created register,login and main page
and a few other pages

can anyone help roughly

here is a demo of what im working on.... http://wapmayhem.co.cc.
/date

[subzero]

sessions in what as you need to tell me abit more....

[wapfuture]

for starting and ending a sessions

well i mean at the moment users at my site can register and login to the main page.. but thats it

i want to add session start ..
and timeout if a user is inactive
because i understand i need this before i can add chatrooms... lol