Welcome to real world :-) go get a free copy of Textwrangler:
http://www.barebones.com/products/textwrangler/ It is the lil bro of BBEdit a professional editor but textwrangler works pretty well. When u need any other software just have a look at versiontracker.com and you will find anything you need. Some other Mac related sites I recomment are macosx.com or macupdate.com. Best thing you can do is read a lot and you wil discover it all soon enuf.
Happy Mac'ing !