Basically, Applescript is a propriteary language which only serves one purpose: to have the official interface to the OSA on Mac OS X. Using applescript for any other purpose, really is not a great idea.
Python, on the other hand, might be considered the de-facto alternative to applescript on the mac when it comes to OSA. you can use the program appscript which is a bridge to applescript from Python. If your interested in using a modern programming language built from the ground up to be readable, understandable, writable, and has a small lerning curve (all the things necessary for a successful scripting language) then Python is basically the best choice.
Here's a great website to get you used to how to use Python, especially coming from Applescript. Its a handy cross reference. Its also a great reference for Python users who find themselves needing to inevitably write a few lines of applescript.
http://aurelio.net/doc/as4pp.html
