how do you make a signature?

Click on Private messages. On the left hand side there are a list of things 'Change avatar' is one of them, theres others also. click change signature and there you are.

or you could go to User CP, but it doesnt really matter

I've never tried it that way.

Do you want to show one on these forums or are you talking about creating one yourself?

If you want to make one yourself, see if you can get yourself Adobe Photoshop. But you can even use MS paint! Have a google for tutorials

thnx guys!

but how do you put pictures on?

you need to use the img tags! So you upload the image to something like http://www.imageshack.us and then paste the url of the image between the [img ] and [/img ] tags (without the space of course)