If interested in doing JavaScript programming, google for PDF on Javascript by David Flanagan 6th edition. Read the first 10 chapters only, maybe even Chapter 12 as well. Then apply that knowledge using the Javascript API extensions known as ProntoScript - There's a PDF DEV guide available in the files section.

I don't recommend PEP3 for starting, I'd stick with latest PEP2.4 and use the latest firmware on remote and any extender.

Learning Javascript will allow you to do some cool things like sliding toolbars, along web access via TCP/IP or UDP. However, if you only want a remote for IR control using a plain-jane user interface, scripting may not be for you.