Here’s a few links to PDFs and other sites that will answer many of the questions about “What do I do with the pelts I have?” This comprehensive manual covers wolves, coyotes, beavers, and all types of animals that are legal to trap.
Click on images to link to information.
The video above also has many links on the side to answer many of your questions.
Basic Sets has information on all kinds of trapping. Here’s their page on how to remove the castors from a beaver.