if I buy about 500 songs on a music download website, am I going to get a credit card statement that's 100 pages long? Or will it just say that I bought x amount of songs for x amount of dolars on such and such a site?

if you agreed to prepay for all the downloads and can use them whenever, there will be just one line with the total charge on your statement. If they bill you as you use them, you may have a lot of entries. Depends on the terms you agreed to, which will be posted on the website. Best to make a printout for your records after re-reading them.