Best Resources for learning and mastering UNIX,Python and Ruby?

For UNIX, opengroup ( a href="http://www.opengroup.org/" rel="nofollow"http://www.opengroup.org//a ) is excellent for POSIX APIs. Also see LDP ( a href="http://tldp.org/" rel="nofollow"http://tldp.org//a ) especially if you really mean GNU/Linux. For the languages, try their APIs ( a href="http://docs.python.org/library/index.html" rel="nofollow"http://docs.python.org/library/index.htm…/a a href="http://docs.python.org/library/index.html" rel="nofollow"http://docs.python.org/library/index.htm…/a ) and the tutorials of your choice (e.g. a href="http://docs.python.org/tutorial/" rel="nofollow"http://docs.python.org/tutorial//a and a href="http://www.math.umd.edu/~dcarrera/ruby/0.3/" rel="nofollow"http://www.math.umd.edu/~dcarrera/ruby/0…/a ).