Every modder has to start somewhere, and these are the basics that almost every good modder has in his or her workshop. If you're new to modding, then click the print friendly button, print out this page, and start to tick of the tools in the following list. Note, these are just selected from the lists below: the tools will re-appear on those lists.
There was a time when computer hardware was very expensive, and software was a tuppence. But now, software rules the world, as the market is saturated with hardware.
More on modding - http://www.bit-tech.net/modding/