It's funny how all these writings miss to explain how to figure out what a function/symbol does. When I want to know what print does in Python, I can type: help(print) and get some useful information. In Lisp there is a function too, that I wish someone told me when I was a freshman: (describe 'print)
documentation is also a good one to know. Common Lisp makes pretty much the entirety of the system available to you programmatically. Browsing the CL Hyper Spec is a good way to discover these things, too.
The specification is (mostly) exhaustive, but would make a very poor introduction into the language. Common Lisp the Language (2nd ed.) [1] by Guy Steele himself gives good background information, but I wouldn't recommend it as introductory text either (and it isn't meant to). Practical Common Lisp [2] by Peter Seibel does IMHO a pretty good job at that.
That is, I love the idea of everything being exposed. And I dream of the idea of interacting with the system this way.
However, I can count on one hand the number of people I have worked with that new you could get documentation that way in python. The world has moved on to browsers being the expected place for all documentation. :(
