Help me please before I freak....

I'm having avatar problems.I have tried to put up acouple of pics and it kept on telling me the size was too big. Not enough room. Had to be 100x100 pixels or something. So I finally got it the right size after about an hour and it says its not jpg. What the fvck is jpg and how do I get it? I know I can be pretty "computer stupid" but DAMN! :icon_piss I've tried other pics that I have and nothing will be accepted. I've tried pics from websites and can't use them cause they are too "big". Please help. I have the coolest pic but.......

Bro if you want I can do the resizes and convertion of other kind of files into JPG
format (this is the format compreession name for graphics) or you can try to do it
yourself if you have a photoshop or grahpic converter you can choose the option "save as" and then when you're chosing the name of the file you will have an option
of which kind of compression you will use for the file and then choose the JPG for it
but I think after that it's gonna have another option that asks you the quality of
compression, you'll be fine with the medium quality cuz this won't interfere in the
real quality of your pic in the avatar cuz the size is very small to even notice it. I
hope this helps if not hit me a PM. Don't explode man! :)

Thanks bro! as you can see I got it. The pic didn't come out as clear as I'd hoped but its there til I find something better. Thanks for the help....