How do you find out how much a silver certificate is worth?

Answer 1

For most bills you need to know what series date it is (i.e the date and whether there is a small letter next to the date), and what condition it's in. Then you can post a new question or look it up in a price guide such as the one linked below.

A few silver certificates come in multiple varieties within a single year, so you may also need to note special characteristics like the seal color. It's normally blue but there were some printed with yellow or brown seals for use during WWII.

Note - the serial number is NOT necessary because it doesn't ID a bill.