Below is a list of online resources for Maya programming.
This is the complete reference site for the Maya product. It contains the latest product development news, example scripts and plugins. If you intend on creating commerical plugins then be sure to look at the Alias | Wavefront Conductors program. This is a program where Alias | Wavefront provides greater development and marketing support to developers who are going to commercialize their products. There is even support for developers who'd like to distribute their plugins as shareware or freeware.
Best known for its indepth coverage of the major animation and modeling packages, the Highend3D, site is also a great repository of MEL scripts and plugins. It also hosts the Maya Developers forum, where you can ask questions of other developers.
This site contains a large number of MEL and C++ API tutorials and examples. The MEL basics are covered as well as some of the more advanced topics. The "How To" sections are interesting for developers needing a fix to a particular problem.
Below is a list of books that cover the mathematics, programming, and computer graphics areas often used in Maya programming. The books are listed, within each area, from beginners to advanced.
Practical Algebra, Peter Selby and Steve Slavin. John Wiley & Sons Inc, New York, NY. 1991.
Calculus Made Easy. Silvanus P. Thompson and Martin Gardner. St. Martin's Press, New York. 1998.
Mathematics for Computer Graphics Applications, Michael E. Mortenson. Industrial Pr. 1999.
Mathematics for 3D Game Programming & Computer Graphics, Eric Lengyel. Charles River Media. 2001.
Introduction to Algorithms (Second Edition), Thomas H. Cormen (Editor), Charles E. Leiserson, Ronald L. Rivest. MIT Press. 2001.
Sams Teach Yourself C++ in 21 Days Complete Compiler Edition (4th Edition), Jesse Liberty. SAMS. 2001.
C++ How to Program (3rd Edition), Harvey M. Deitel, Paul J. Deitel. Prentice Hall. 2000.
The C++ Programming Language (Special 3rd Edition), by Bjarne Stroustrup. Addison-Wesley Publishing Co. 2000.
Effective C++: 50 Specific Ways to Improve Your Programs and Design (2nd Edition), Scott Meyers. Addison-Wesley Publishing Co.1997.
Efficient C++: Performance Programming Techniques, Dov Bulka, David Mayhew. Addison-Wesley Publishing Co. 1999.
Computer Graphics: Principles and Practice in C (2nd Edition), James D. Foley, Andries van Dam, Steven K. Feiner, John F. Hughes. Addison-Wesley Publishing Co.
3D Computer Graphics (3rd Edition), Alan H. Watt. Addison-Wesley Publishing Co. 1999.
Graphics Gems I, Andrew S. Glassner. Morgan-Kaufmann Publishers, San Francisco, CA. 1990.
Also see Graphics Gems II, Graphics Gems III, Graphics Gems IV, Graphics Gems V.
Geometric Tools for Computer Graphics, Philip J. Schneider, David H. Eberly. Morgan Kaufmann Publishers, San Francisco, CA. 2002.
An Introduction to NURBS: With Historial Perspective. David F. Rogers. Morgan Kaufmann Publishers, San Francisco, CA. 2001.
Subdivision Methods for Geometric Design: A Constructive Approach. Joe Warren and Henrik Weimer. Morgan Kaufmann Publishers, San Francisco, CA. 2001.
Computer Animation: Algorithms and Techniques. Rick Parent. Morgan Kaufmann Publishers, San Francisco, CA. 2002.
Advanced Animation and Rendering Techniques. Alan Watt and Mark Watt. ACM Press, New York, NY. 1992.
Principle of Digital Image Synthesis, Andrew S. Glassner. Morgan Kaufmann Publishers, San Francisco, CA. 1995.
Texturing and Modeling. David S. Ebert et al. Academic Press. San Diego, CA. 1998.
Realistic Ray Tracing. Peter Shirley. A K Peters Ltd. 2000.
Jim Blinn's Corner: A Trip Down the Graphics Pipeline. James Blinn. Morgan Kaufmann Publishers, San Francisco, CA. 1996.