Feel free to PM me if you have questions. I will admit my knowledge of mine is still pretty basic. I'm learning daily. A lot of the routing through aux type things are still confusing to me but I have gotten a pretty good hold on fat channel, FX, sends and returns via firewire, etc.
I will add this. As the presonus is a firewire mixer be prepared to purchase a new firewire card even if you already have one. They are picky about what cards they work with and seem to only like a few chipsets. Presonus has a list on their website of all the cards that it will work properly with. I went through almost the entire list before I found one that was even stocked at any of my usual online vendors.
If you are using a PC I would be happy to post up the link for the card I got, if you're using a laptop may god have mercy on your soul (just kidding, but unless it's an old laptop with an expansion bay you are hosed).