I agree with everything jigman says.
When starting out, you may want to experiment with floats. The wood floats can be expensive, and you will lose a few while learning... I like the newer foam floats that are dark grey (I forget the brand).
You can also add bait or a pink rubber worm. You can find jigs that are made just for this purpose (harness style). Scent is a good thing to try, but be careful not to mess up your marabou...

I've also been experimenting with jigs fished without a float. Depending on the type of salmon/steelhead, the type of water, and water conditions, the technique will vary. Try light weight jigs cast and retreived with a slight up and down jigging motion. If the fish won't hit them in the upper to mid water column, try a heavier jig cast out and walked back up the bottom to you. Be prepared to lose a few jigs this way! I've had good luck with silvers and chum this way. Haven't tried it with others yet. Just don't be a snagger! If you start snagging, change your technique or put on a float...
And finally, you can fish spinners under a float as well. This can be very effective when the fish prefer a slower presentation. Just pick spinners that produce a lot of action with little resistance. Try dead drifting (the currents will move the blade just enough) or applying a little back pressure so the spinner is just downstream of the float.

Jigs are great because you can work a lot more water. Chuck you float up into that canyon that is impossible to fish, or free spool it down into that nasty log jam that eats drift gear. Just always be ready for the strike. A lot of fish are missed due to slack in the line.

Good luck!
-Chad