Q About Python Ipo Drivers

is there any good tutorials about how to use Python Ipo Drivers ?
for Ex what is the Expressions i can use to control object by another ?
can i use it in Rigging Like maya ?

Thanks for you all
And sorry for my english

http://www.google.com/search?q=pydrivers&sourceid=mozilla&start=0&start=0&ie=utf-8&oe=utf-8