This is a rig I came up with before fishing for big catfish. I've only used it once but it works better than anything else i've tried.
Step 1: Materials
For this rig, you will need...
A circle hook (size 4/0)
a 1/2 or 1 oz. dipsy swivel sinker
a barrel swivel (size 5)
a treble hook (size 2/0 or 3/0
a reel with 20 lb line
a spool of 17 lb line
Step 2: Add a Treble Hook
tie on a treble hook (I use a palomar knot) with a 4 ft piece of 17 lb line
Step 3: Add a Circle Hook
Snell a circle hook about 3 inches above the treble hook.
Step 4: Add the Swivel
Tie a swivel onto the end of the leader.
Step 5: Add the Weight
Slip the sinker onto the 20 lb line on the reel. then tie it onto the other end of the swivel.
Step 6: Tips
The reason for the 17 lb leader is that if the line breaks, the it will break on the 17 lb side and save you the swivel and the weight
When fishing for toothy fish, i like to change from the 17 lb line with a wire leader.
Step 7: Try It Out
Now you can add a live bait onto the hooks and start fishing!