Hi ^_^ *duck*
I know I've posted about this several times, but 
anyway - I'd written a guide about cel supplies 
(specifically books and bags) - you can get to 
it from my link above by getting from the Anime 
link to Hall of Wonders and it's linked from 
my Cel Collection. The exact URL is:
http://www.oion.net/plug/qnd/cel-supplies.htm
(Warning - big document -_-') 

The easiest thing you can do, however, is pick up 
an archival scrapbook from Itoya (product line 
"art profolio") from any well-stocked art shop.
^_^