Mike,
If your test is using degrees of carbonate hardness method. I usually try to stay beween 7-12 dKH. if it is in milliequivalents per liter you want it >3meq/l. But always remember that there is always a high- low relationship between calcium and alkalinity.
I would refer you to any article written by craig bingham. you can find him at reefs.org they are a great resource. They have an archive of aquarium frontiers magazine that was around in the mid 90's that had some great articles. just go to the library at reefs.org and you will find all of the aquarium frontiers magazine articles.
Keep on reefin'
James