I noticed that the WiNG Best Practices and Recommendations document has been rebranded by Extreme. It was introduced by Zebra back in early WiNG 5.x days around 2011 or 2012, but what I want to say that this has been my "go-to" guide for information on how to best setup your WiNG wireless equipment.
Whether you are struggling with DHCP Option 191 adoption, adoption policies, MINT levels, Clusters and much more, you owe it to yourself to have a look!