As you can see if you take a look at my tag-cloud, I really like AppleScript. It is so easy to implement simple tasks with a few lines. Most in OS X included applications support it and also many others. Shell scripts are also includable. It is so easy if you compare to other systems. Most parts of Linux are of course highly scriptable which I really like. It is a bit catchy to get into that but surely remunerative. Anyway, with AppleScript it is really easy to take the first steps. You can tell application “Finder” to empty the trash. Just as I wrote it.
tell application "Finder" to empty the tash
Or lets say "Hello World".

You can control many apps and your system. But not only that. It can handle variables, loops, functions and whatnots.

Take a look if you want to get more out of your Mac. There is a great page with many resources: http://macscripter.net/

I also recommend this free book for AppleScript starters by Bert Altenburg. http://www.fischer-bayern.de/as/as4as/AS4AS_e.pdf It teaches the basics. And with the help of the functionlist (+shift+o in the scripteditor) you have the knowledge to create quite useful, individual tools.