I'm no expert with only just setting up my first wet/dry sump. So I'm sure others will certainly jump in to help. In the meantime, here's the diagram that came with my sump.
My specifics were as follows:
I got a great deal on a 140gal "Reef Ready" with two overflows built in each side and pre-drilled, so I didn't use the overflow box that came with my sump. I did add ball valves to both the drains and the returns for my peace of mind and ease of changing things out should I ever need to. I'm assuming you don't have a reef ready aquarium, but I've seen where others have still added inline ball valves should they want to remove the sump for cleaning or replacement. I also added a "T" joint to split my returns.
Given my tank was Oceanic and my wet/dry was from Eshopps, I needed to adapt the 1 1/4" drains with reducers to 1" for my Eshopps intakes. The one thing I did learn from this is to be sure to use plumbers tape on all threaded joints and silicone for added measure allowed to cure for 24hrs and adjustable clamps. Any ACE, Home Depot, or Lowes plumbing department techie can help as well. I just took my diagram and a sample hose with me.
As you can see my HOB filters are still in place until the wet/dry has fully matured over a few weeks or so, then remove them and add the Oak canopy.
Hope that helps get you started,