I know I'm computer stupid but how can I find out how this site works? How do you put a picture or icon on you profile and all that stuff people do on here?

Go to control panel/options (top right) then edit profile...then you paste into "avatar" your picture location.
If don't already have your picture on the 'net then you can upload it onto this site, open it on here then right click, select properties and then copy and paste the address into your avatar box....

It is a LOT easier than it sounds.....