Obviously, we hope that you will want to work with a design group like ours, but even if you don't we are very happy that you are paying attention to the room. It's for this reason we've spent a huge amount of time putting together a resource section with many articles, simulators, and tutorials. So, if you don't use a group to help with the design, then do a lot of research and reading. One of the best books is Alton Everests, Master Handbook of Acoustics. It is a great overview on the subject and touches on just about all facets of small room acoustics.
Rives Resource Page
Rives Resource Page