Members stuff

[gt_so_dumb_lt]

hey, ive never done a site with members before, so i need to know, or if anyone could point me in the direction of a good tutorial, about getting a system set up for members of a website… i need to include, a way for the webmaster to input new members details (so kinda like a signup page) , a password gate, and a way to display who is online (that bit where it says such and such members are online, and so many guests)… any help would be appreciated, thx