Hi John,
This is a great opportunity for you.  Here is a link to me starting from scratch and the steps I took.  Have fun
 http://www.net54baseball.com/showthread.php?t=116487
 
http://www.net54baseball.com/showthread.php?t=116487
I suggest you start with:
-color choice
-What are the key pieces from your collection that must be featured? Then fill in around them
-what doesn't make the cut for inclusion?
-shelving/cases/where can I make the best use of space