I just got a MacBook Air and I would like to download the Python programming language and an IDE like Pyscripter. Could someone suggest what to download and any threads on this site that I might want to read before getting started?

Python comes with an IDE called IDLE; I'd suggest reading the beginner threads and also decide which version of python you're going to start with, python 3.2.2 is the most recent version, there are more packages available for python 2.7 but the future is python 3; python 3 is backwards-incompatible with python 2. A good GUI package to start with is tkinter it's built into the python standard library. There a few other IDE's than IDLE available, but that's up to you, and there are plenty of good beginner guides to python.