ALSO:
There are many text editors out there and everyone feels theirs is the best :P
I personally use UltraEdit:
http://www.ultraedit.com and my reasons for thinking it's the best out there extend beyond it's usability and into the fact they update all the fucking time. It's fantastic and VERY feature rich.
On OS X I use TextMate:
http://macromates.com/ unfortunately the developer dropped the project quite a while ago but the community support is awesome and it's pretty feature complete, especially as far as os x apps go... It's preferred by a lot of developers but, as always, it's a personal preference thing.
You'll also want to setup a local dev environment. If you want to run the LAMP stack and have an extra box to install Linux on you could buy the book I wrote:
http://www.amazon.com/Setting-Up-LAM...dp/0782143377/ Hahah but it's a little dated now. If you wanted to buy an extra box look at picking up an Asus eeebox. The base model with an extra gig of ram comes in at like $230, has super low power consumption, and runs like a top. I personally use three running Debian Linux and they're fantastic.
If you're just looking to mess around in Windows then I would HIGHLY recommend WAMP Server:
http://www.wampserver.com/en/ It's a very handy little one stop shop app that installs all the services you need in a little bundle, updates easily, and has a little GUI to it.
That's all you need in the line of software and hardware. Hope that helps :D