Okay, I get how to make a banner, but can I have some links to apps on certain sites that make banners?

I use Polyvore. It's suppose to be about fashion and clothes but you can use letters and cool pictures, too. :)

Uh, I use photoshop. But if you don't have that then just use word or paint *shrugs* I don't go all professional on these banners, I just keep it simple ^^
Good luck with ur banner-making :)

I use GIMP now, but Picnik does make banners. You just go to the collage maker and pick either the setting of how many pictures you want and mess around with the ratio until you get it to look like a banner shape. Then click next when you're satisfied and then crop the photo to "800:100" and you should get a banner. It won't be fantastic, but it's a banner nonetheless. Hope that helped. :)