One of my favorite advice on Pragprogs "From Journeyman to Master", is to learn at least one new language every year.
Afaik Scott Hanselman said it even better, "if you know a static language(e.g. C#, Java, scala), then try to learn learn a dynamic language (e.g. Ruby, Python, Perl), know a dynamic language then try a static language, know both then try a functional language (erlang, haskel, clojure).
So if you are planning to put your in static language, here is the good starting point to learn C#:
http://channel9.msdn.com/Series/C-Fundamentals-for-Absolute-Beginners | C# Fundamentals for Absolute Beginners (Channel 9) | C# Fundamentals for Absolute Beginners (Channel 9) | Want to learn a different language? Over the course of 25 episodes, our friend Bob Tabor, from www.LearnVisualStudio.net, teaches you the fundamentals of C# programming. Tune in to learn concepts appl