If you want to learn to model, basically the first thing you'll have to learn is polygons. NURBS may also be an option, but they have a much steeper learning curve and aren't as straight forward. Once you get past the basic tools (extrude, split polygon tool), you'll want to start getting into the more advanced ways of creating polygons, such as create face and append tools. After that get a good handle on all the tools and understand the principles of edge loops.
http://wiki.cgsociety.org/index.php/Edge_LoopOnce you have figured out edge loops, the next thing would be to practice, practice, and practice different ways of creating something. Sorry this is such an overview; if you could be more specific on exactly the help you're looking for, we might be able to pinpoint a better answer. Also, Google will be your best friend when learning anything Maya.