The range of options in WavePad basic - there is a commercial "Masters" version - is impressive. You can add effects, fades, split tracks, merge tracks, and much more. Performing all of these tasks is easy, and easy to undo if you make a mistake. It's certainly user friendly, and the fact you can import more or less any sound file format makes it incredibly accessible for anyone (there's no need to mess around with file conversion).
As well as importing from your hard drive, you can also import directly from CD, and there's a tool to burn whatever you want. There is a tone generator, and even a text to speech generator, so you can express yourself with a robotic voice.
There are tabs at the bottom of the edit window for you to move easily between open files, a zoom tool so it's easy to highlight exactly the part you want when editing, and the highlighting itself is really intuitive, allowing you to apply effects with precision.
The one function I think WavePad is missing is a BPM analyzer - although this is sometimes unreliable in other programs, it's a nice feature to have.
For anyone that wants to mess around with their sound files - WavePad is a great and lightweight program to use.