Yes I would go along with everyone else in recommending audacity. It is very basic, which equally means it is very easy to use.
For the price (fourth-fifths of s*d-all), it's fairly good - although I don't use it myself in day-to-day use. I much prefer the "standard" Audtion, which is the new name for Cool Edit after Adobe took it on. Then there's my affair with Sadie, oww yes ;-)
However, Audacity is certainly a good start. Now - Who wants all these razor blades and chinagraph pencils ?