If you need clean out noises from a sample then try scooping out some frequencies with narrow band EQin. If your cleaning it because it's shit quality though, then just don't bother. If its voices your after you'll generally want to boost mid frequencies aswell, since human voices are in this frequency range. Obviously the actual frequencies vary depending on the voice, but have a play around. Use a wide band when boosting frequencies if you want to retain a "real" sound. Using narrow band on EQ peaks can make the voice sound artificial.
Another thing, you can grab audio using VLC media player from any media source, using the "stream/save" function in the open dialog. VLC is free aswell. I use it for grabbing entire audio from films then cut out sections i might use.