u r probably going to get some backlash for this question.
anyway..under the link "Newbies Corner" is this link called "articles and guides" which contains THIS particular link called:
User guides to posting images in clubsnap forum http://www.clubsnap.com/forums/showthread.php?t=94574
131 posts and you haven't seen any of the existing newbies guides or any of the pictures in the photo gallery forum categories??? You could just use the same dimensions as the pictures posted there, no?