I bought bulkheads at Tractor Supply, which is also where I bought the rubbermaid tubs. I used 1 1/4" bulkheads. I used hole saw drill bits to cut the right size into the tubs. The bulkhead slides through the hole, the gasket goes on the INSIDE of the tub, and the bulkheads I bought had two gaskets so I put one on the outside too. The bulkhead is also threaded on the inside of it so I screwed 1 1/4" PVC pipe adapter into the bulkhead. Then I glued PVC pipe into the adapter. I DO have ball valves between the tub and the pump though, but they are wide open during normal operation. If anything happens to the pump, I can close the ball valve on the input AND output side of the pump and remove the pump.
Here is a pretty good place to buy bulkheads if you don't have a place locally. I bought my skimmer from Aquacave.
This is what my plumbing looks like going into and out of the return pump.
Before I put this into operation, I DID put another ball valve on the output side of the pump. I also have one behind the tank on the return line so I can control the flow at the tank so I can see what's going on. Also, if something drastic goes wrong, I can just close the ball valve behind the tank and THEN go downstairs to unplug the pump.
I'm building a controller so I'll be able to turn the pump off from any PC in the house but you might want to think about connecting a two way wall switch into the wiring for the pump. The pump DOES simply plug into an outlet but I think it would be nice to be able to reach behind the tank, throw a switch, and the pump is shut off. But you'll also want to be able to turn the pump off while in the basement, for when you're doing water changes and maintenance on the pump. Therefore, it would be nice (but not necessary) to have a wall switch at the tank AND in the basement that controls the pump.
Sorry, not trying to make it more complicated for you, but that is what I wish I had done.