Help on Custom Screenshot

Hola folks.

Could be a noobish question to some and a helpful one to many. How do i design or make a screenshot work as the title screen when people download the map? Like when you dl Enfos and you see his Title sig shot on it? I have took a few screenshots but the prob is i can't get them to import right or anything. I could be doing this all wrong. If someone out there that knows or has done a custom screenshot for the title please leave a noobish step by step method for me... and for others that are curious as well.

Thanks for the help.

I haven't done much with that sort of stuff but I assume if you can get it in the right format it should work like any other title.