Do you mean your signature and avatars,Dee?
If you go to the user control panel..top of page..then to profile..look down left hand side of page you will see edit signature,edit avatar etc.
You can up-load a pic from your computer as long as it is only 80x80 pixels and not huge in Kb!!I think it's something like 30ish.
If you want to put a pic actually in a post when you are writing an answer look down to the bottom of the post reply box and you will see a tab that says 'upload attachment' click on it and browse for your pic,follow the instructions.Again make sure your pic is not too big ,about 400 is about right.