Setting up hardware sends in REAPER (+Presonus Digi FS)

Hi all,

Generally when I record FX I just send the signal of whatever I'm playing to a FX unit, and record that signal. But now that I have a Presonus Digimax FS hooked up to my interface (Presonus 1818 VSL) via ADAT, I was wondering how I would set up sends in REAPER to FX units (Ensoniq DP/4, Boss SE-50, maybe a couple guitar pedals).

Unfortunately, I am a complete N00b at this so I need step by step. Do I take the inserts on the back of the Digi FS and sent to the "ins" on my unit, what about returns?

And once this is sorted, what do I do in REAPER to enable all this to happen. Again I am sorry for these simple questions, but I have yet to set up sends in my music making. I always used VSTs, or recorded the signal wet.