building new studio need help

I am new to this site and it is great with lots of info. My question is we are building a recording studio in one room of our basement. The Room is already finished. Three of the walls are concrete. The room is Approx. 12'X20'. The only framed wall runs the 20' span. The wall is not a straght wall, It has two built in closets on eather end with egress door in the center. Heat duct is in the ceiling in middle of the room. We have limited funds, So what would be the best plan to make this into a funcitional recording studio. Any info would be great. Thanks Marty