1. First, read the new rules coming out...most of the above sources are based on the old rules. They will appear in the daily digest at FCC.gov
2. You can find your coordinates for your site at
http://www.trails.com/maps.aspx (the old topo-zone). These will be nad 83 datum, FCC uses older nad 27--minor differences, converted on FCC site.
3. FCC has a channel finder program here:
http://www.fcc.gov/encyclopedia/low-power-fm-lpfm-channel-finder
4. Another way to do it is to print off the minimum spacing rules (as modified from the rule making--will be 73.807), then use the FM preliminary study program at:
http://transition.fcc.gov/mb/audio/bickel/FMprelimSTUDY.html
for a frequency you think might be open. One limiting factor on siting are existing translators, these rules are somewhat hard to follow since the minimum separations are determined by the coverage of the translator, which is determined by the power/antenna height.
REC networks will be updating their programs, these are more flexible since they show areas where there might be a channel around your location or city, not just at a certain point. Figure coverage at 5 miles out at most from the antenna site--so what may be an open channel may not be that useful if it is too far from town or blocked by hills.
Once you have a possible channel, be aware that you must form an organization that will be applying. Suspect the applicant priorities won't change--educational institutions are likely to have priority over established non-profits over newly formed organizations. Also likely that non-profits will still need most board members from the community where the station will be licensed. We'll see.