An introduction to low power FM transmission (or pirate radio basics...) part 3

What frequency should i choose?

Choose a frequency nobody is else is using, simple as that!

Most importantly!

Make sure you dont interfere with other (especially officially valid) radio users

Before you transmit, (days before even!) roam the area you will cover with a good radio, make sure nobody is using your desired frequency.
Find a quiet part of the spectrum, make sure your signal does not break-in(bleed) onto an adjacent used frequency.
Find out how your rig behaves at full power (cold, warm and hot) in an isolated area, is there frequency any drift?
Get an SWR meter (and use it!) http://www.smeter.net/feeding/swrmeter.php

Finally, read all you can about the subject. And note regional differences such as pre-emphasis

http://www.freeradio.org

Radio terms and abbreviations http://www.dxing.com/radioterms.htm
ARRL abreviations http://www2.arrl.org/qst/aguide/Abbrev_AWE.pdf

If your not creating a nuisance - then you may just get away with it!

Happy raving :)