As in the two separate? Python is a cross platform language as it compiles into byte code similar to Java. For Python I would suggest looking at something like this: http://www.nervenet.org/pdf/python3handson.pdf
For Linux command line use this (bash is the language that linux uses in the command line): Advanced Bash-Scripting Guide
For the Raspberry Pi itself I found a lot about using Linux and a whole chapter on Python in the Official Raspberry Pi User Guide which can be purchased at amazon.com or most bookstores.
If you just want Python, I have heard that http://learnpythonthehardway.org/book/ is a good resource (if you don't mind the advertising for their videos). The book is free to read online but they sell it as well. Don't let the name scare you off, I hear it is still good for people new to Python.
If you are getting started with Linux, I recommend watching Nixie Pixel https://www.youtube.com/user/nixiedoeslinux. She is great about explaining linux in common terms and showing how to do things with Linux. She does not specialize in Raspberry Pi, but there is a lot that is common no matter what hardware you run Linux on.
