Recommendations for 802.11 wireless site design guides or physical access point placement design guides?

I haven't done much wireless at enterprise level. I need to deploy access points for a small/medium campus and I'm looking for some reading on how to properly determine locations for access to get the best coverage and minimize 2 & 5 GHz congestion. In the past I've done 'guess and check' for access point placement but I figure there had to be a more scientific method of determining AP placement.

Thanks!