Music licensing in general is a big topic, and below are a few articles to help you learn more about the common types of licenses out there. Remember you still need take responsibility for learning licensing personally and consult a lawyer when appropriate!
Good luck!
Overall Licensing:
Music Licensing 101: A Complete Guide for Beginners
ABCs of Songwriter Jargon: A Glossary of Songwriter Terminology
I Want to License Some Songs: The Songwriter's How to Guide
Mechanical Licensing:
So You Got a Cut...Now What? The Mechanics of Mechanical Licensing
Administrative Deals:
Administrative Deals in Music Publishing
Recording and Releasing Cover Songs:
Do I Need to License I Cover Song if I Give it Away?
4 Tips on Getting a Mechanical License for a Cover Song
Sync Licensing for Film TV:
A Simple Guide to Signing the Best Sync Deal Possible
Sync Licensing Explained: Read this before signing with a music library