Many stores sell scrapbooks and magnetic photo albums. There are many to choose from. I suggest starting off with something medium to large sized. It is much easier to spread out the stuff you have then transfer all that stuff to a larger book if you run out of room. Here are some other important archival hints:
It's always important to have items (not just photos) to put in the scrapbook. It adds dimension and character to your book. And don't forget smells! Your olfactory system (smelling) is one of the senses most strongly connected with your memory. Spray some of the perfume you wear to prom on the inside back cover.