www.codecademy.com – start here if you are completely new to python and just trying it out. You will need to create an account first and select python. This site has online lessons, no editor or installation required.
www.groklearning.com – some basic python hour of code lessons for free, learn python while you take on programming challenges.
www.inventwithpython.com – you can download an pdf ebook from this site and the lessons will teach you python by building games
http://www.learnpython.org/ – online tutorials and online editor
http://learnpythonthehardway.org/book/ – free HTML version of the book that you can do yourself
Lengthier Courses for Older Programmers (video-based course lectures)