The ADSR sounds like a good suggestion.
Other than that, you have a LOT of stuff to explore. I would sit down with each module for a day to a week, and mess around with it, and read the manual. See how each plays with the others in the rack. You will learn a lot, and you will figure out which modules need to be moved.
Commit to doing that with at least half of your modules (the ones you don't completely understand) before you buy any more stuff - feel free to research other modules, but don't buy them immediately.. Then your next purchases will be much better informed.
-- naught101
I see.. Any ADSR recomendation ?