PappaG,
in fact, i've seen many sound recording/editing applications but using windows standard sound recorder is simplest. it can do everything you need to do with an announcement file, i.e. crop it, increase/decrease sound level and convert it to the other formats, and it's so standard that every windows starting from 3.1 does have it.
one little hint: when you want to operate over some announcement, better don't convert it to the val board format (CCITT mu-law (not pcm), 8000 khz, 8 bit, mono) until you're done with sound adjustments. i don't know why but if you convert it first and then try to adjust sound level, the program won't allow you to do it. adjusting levels in a 16-bit format is okay.