If you are using Maya 2011, it comes bundled and tied to py 2.6.4. You do not need a separate installation, even for pyMEL.
If you want to learn Python on your own before applying knowledge to a 3D application, then pretty much any Python 2.x will do, version-specific functions come into play for a while if you are on your first steps. 2.6.4, although, of course, it will be a good choice, as it will be consistent with what you can use in Maya and Softimage directly from the gate.
Stay away from py3k, since adoption in our area seems to be a long way off.
In terms of resources, for Python and Maya together, there’s practically nothing, but most of the programming-oriented material I’ve seen has been published to the extent that only a few notable exceptions, such as Gould’s stuff, are usually between overwhelming and simple amateurish .
, , ( O'Reilly, Python ), , StackOverflow , , , API- Maya.
pyMEL, , .
, , , Pythonic, .
pyMEL, 100% , , .