Your intellectual property rights
As an artist, you have specific and well-established legal rights, as well as general protection under the law on things like employment or getting paid.
For a good overview of some of your rights as an artist, listen to Aaron Wood, formerly Registered Trademark and Design attorney and Head of Trademarks and Brand Protection at Briffa. Aaron has worked with a number of major brands in the arts and entertainment sector in relation to exploitation of their work.
The Artlaw section goes into much more detail on these basic rights, which every artist should be aware of in order to protect their work, understand their legal position regarding contracts, and prevent getting ripped off in negotiations.