Tom,
Welcome.
A dedicated room is a very smart first step. Most audiophiles severely hamper their system enjoyment with rooms that are too small, oddly shaped, or have to deal with any number of domestic limitations.
Bigger is better, but only until the shape gets "weird". Read Floyd Toole's "Sound Reproduction" for good advice for room shape. Before finding Toole I followed Cardas for setup and room shape (near to the standard Greek golden rectangle with ratios of 5:8 ) which fits into Toole's advice and seems to work well. Just avoid simple ratios like 1:2 or 1:3 to reduce echo. Insulation is critical too in which attention to detail is critical.
