I will try to explain my drowning rig sets the best I can. Put one end of the wire to a heavy object and throw in water deep enough to drown the animal you are targeting. Your trap must have a drowning rig on it. Some come with them on them and the duke traps have a D swivel on the end that works. A drowning rig is something that allows the trap to slide one way but not the other. If you have duke traps put the wire through so the trap will slide into deep water but not towards the bank. Now stake or tie the wire to the bank. You want the wire straight so the trap will slide better.
Lure is not a REAL biggie. There are many commercial lures on the market that work. Lenons, Carmans, Hawbakers, etc. I have used Hawbakers muskrat lure #1 succesfully. For bait on rats use apples or carrots. For coons I use fish heads mostly, but marshmallows, sweet cakes, tuna, sardines, etc. will work just as well.
Just make sure your on location and you will catch fur regardless of what type of lure you are using.
Good Luck,
Zach Ellis