Technically, a scrapbook can take on any form you can envision. Will yours be made from newspaper and macaroni? Regardless of what you see in your scrapbooking future, there are a few basic things you need: scissors, glue, and cardstock.
Scissors. Plan to spend between $5 to $15 on a pair of good quality, sharp, straight-edge scissors. You'll be using your scissors a lot, so it makes sense to put a little bit of money into this important tool.
You can invest in a paper trimmer or paper cutter if you prefer. Depending on size and quality, they could run from $10 to $70. There are tons of decorative-edge scissors you can buy to add some interest to the edges of your paper or photos when you cut them. They can be a lot of fun, but they are a nice-to-have rather than a must-have item.
Adhesive. There are a variety of ways to stick your images and embellishments to the page, but you're likely to need nothing more than a good glue stick. It's easy to use and comes in an acid-free, photo-safe formula. If you want to be able to remove photos from your scrapbook pages, purchase photo corners. You insert the corners of your photograph into the paper corners and glue them to the page. Then you can remove the picture by gently pulling its edges out from inside the corners, which stay in place on the page.
Cardstock. Pick up a pack of multi-colored 8.5"x11" Cardstock. You can use it to mat your photos, create tags and blocks where you can write text to add to your pages. If you're using an 8.5"x11" scrapbook album, you can use the Cardstock as solid background pages for your album.