Hi Sarah,
I've only recently started using PSE2 myself but there are some great tutorials on this site that you should check out. When I'm doing my layouts I usually edit my photos first before I import them onto my background. Also, I usually set my page size in a new document then copy the background into it, I don't risk saving my layout over it by mistake then!
HTH and welcome to a great website !!
Pam.
