Hey Chris, any luck yet mate,
Rossco and Lucas got it spot on. When doing it Lucas's way you may need to resize pics first. That may be why you had trouble first time round (pics to large) it should tell you on top section of the manage attachments window when you try uploading. it should also tell you in the bottom section what sizes can be used. if you do need to resize this is a top little program, easy to use and can resize heaps of pics at once, dont have to do 1 x 1.
http://www.fotosizer.com/, Good luck
Cheers Pete