For the sump you will need some type of overflow.
You can make one or buy one. Basically the idea is you have two boxes, one inside the tank, usually it has notches cut in it to keep fish and such out, a big u-tube, and a second box outside that has a drain. Someone posted directions on how to make a do-it-yourself overflow and I think the article is located in the archives.
As for the skimmer, it can be in sump or on the back of the tank, Probably better for in sump in case of overflow. To hookup you hook a pump to the inlet which is the connection with the thin air hose coming up, the other connection is for the return and should be directed back into the tank. Then when you turn on the pump, water goes in, sucks air in through the air tube (which should have the open end above water), does its thing and then goes out the outlet where the valve is located, After you let it run with the valve full open, slowly shut the valve to get the desired amount of foam going into the collection cup.
I hope this helps, if you have any questions that I can help with feel free to e-mail me.
I know you didn't ask about the prism skimmer but I figure you might have questions about it. That just hangs on the back of your tank, tighten the screw thing to keep it in place. Then just plug it in, the pump should slowly take water up return back to the tank. The air tube on this skimmer has two holes it can connect to at the top, one is for starting the skimmer, it does not let air in, the other lets the air in, once it is running you will want to transfer it to the one that let air in. Also there is a valve on the inlet, shut the valve part way and slowly open until the desired foam is in the collection cup. (note on the prism opening the valve causes more foam, on the TS-2000 shutting the valve will cause more foam)
Michael