Have you explored the music library recently? You might be surprised by the amount of books about contemporary music composition, improvisation, composition philosophy, artistic processes, etc. are just waiting to be read. Books will be all over in the ML and MT sections, but you might want to pay special attention to the MT40-MT68 (instruction on compositional and improvisational techniques), ML197 (history of 20th and 21st century music), ML410 (biographies of composers), ML430 (history of composition), and ML3800 (philosophy of music).
If you're wanting to browse modern scores make sure you visit the Double and Triple Oversize sections in the Basement of Langson Library. Many contemporary large ensemble scores live there.
Have a question, need help, or want to show off your awesome finds? Email the Music Research Librarian, Scott Stone: email@example.com