I would reccomend perl as a good starting language. There are tutorials for it stickied at the top of this section and you will have to download the interpreter at
http://www.perl.com .
If you need anything else along the way dont be afraid to ask.
EDIT: Just realised the perl page is a bit tough to get around, so if you want to download perl go to here:
http://www.activestate.com/Products/ActivePerl/?_x=1
And click "ActivePerl 5.8.8.817" under current releases, the rest is easy.