I know for def that Wavepad is the full thing, as I use it myself (first link)

I did flick through the others and filtered out ones that were trial version, and only looked for freeware and shareware, so you should be okay.

Wavepad is good - you can simply split MP3's (or other filetypes) and cut out sections, but can also do SOOOOOO much more with it. No instructions as such, but I never read em anyway - just fuck around with it for half an hour and it's easy as piss to use