I just registered my inflatable boat with a 30lb thrust electric motor. You DO have to register the boat, however, you do not need the boater safety card with the electric motor. Give 'em a call, they are very helpful and fast. . I got my registration within 2 days. Make sure you pick up the OR boating regs and read it through
As for trolling, I like to use a 3-way swivel with varying size weights on one end of about 3' of line and the other way goes to a high-quality swivel and then the lure of choice (2-4' leader). Lures I like to use are spinners (I use p.martin "big belly" spinners, Mepps aglias, and home-made spinners), kastmasters (gold, silver, and blue/silver), spoons (rainbow needlefish), and Gulp! minnows or Gulp! worms.
I try to avoid using lead or plastic, so, my trolling hardware varies from the standard hardware a bit. Plus I keep it relatively simple... after all, it's just an inflatable boat. I use Bioline Biodegradable fishing line. Typically 6-10LB mainline and to the weight (lighter than some folks for less water resistance) and 4-6LB for the leader. I typically use Eco Weights in either the bank sinkers (quick and easy) or I stack up the worm weights on top of a glass bead on top of a barrel swivel (less resistance and precise weight).
Without sophisticated equipment and hardware, my technique is to let out the line slowly while holding it between my fingers and pinching the line then letting go and then pinching it again so it's coming out about 1 foot at a time (more important to be consistent with each letting out than exactly one foot). I keep count. This allows me to control my depth relative to other times though I don't know what that depth is. But, I know when I'm catching fish I was "x ticks out" at some location and can get back there again on the next troll.
I troll in the slower speeds of my electric motor in zig-zags and S shapes. This will make the lure vary speeds and drop and change direction. I also give the rod tip a quick pull up and drop here and there.
Cheers,