Well Newbie I'll try to help a little. If your mooching herring and jigs in the right places you will catch fish, when they are there, so a downrigger is not a must have. The main thing is to find the bait and fish where it is. I don't really know the what area you are fishing so I would suggest checking out this site. It has a bunch of really good info for the begginer saltwater fisherperson.
Good luck........http://www.salmonuniversity.com/