Once your boat is set up with rods, holders, GPS, and trolling motor you'll want to start with one jig per line (your choice weight of jig, mine is 1/16th with southern pro curly tail grubs). Start trolling and get your speed up to .8 mph and get 'er steady. I dont use line counter reels so I just give a GOOD cast on each rod, starting on the inner most rod/reel working my way out on each side of the boat. By doing this you can cast to the outside of your last line casted out instead of trying to cast between 2 lines being pulled behind your boat.
Now...start trolling towards the shallow water watching your graph for depth and the GPS for speed. Keep a close eye on the rod tips and keep trolling until you see rods bouncing because the jiga are dragging bottom. That's how you learn how deep your jigs are running. There are many ways to change how deep you can make those same jigs run in different depths. You can shorten or lengthen the amount of line out, slow the boat or speed it up, or go to lighter or heavier jigs (2 jigs per line, adding splitshots also can be done). Also line size makes a difference as heavier line is of larger diameter and lighter line is smaller diameter. I use 6# hi-vis mono on my trolling rods. The high-vis helps you see the line when you need to cast a jig out between your lines after you catch a fish.
My reels are all UL spinning reels and I run the drag pretty loose. Reason for that is when a jig hangs brush/bottom the drag will slip until you get your rod in hand and either straighten the hook or break the line. You cannot stop the boat or all your jigs could hang.
To begin with, I'd say get your boat set up, tool up with rods, reels, and jigs and get on the water. LEARN how deep your jigs runs. Then your next step is going to be finding fish/bait by using your graph in likely places and seeing how deep theyre holding (again, by using the graph), and setting your lines accordingly. Keep in mind...fish feed up, so dont run your jigs 13' deep if the crappie seem to be holding 10' down in 20' of water or you wont be catching many.:rolleyes:
Do your part and get started by getting rigged and ready. Once you begin doing this then be specific as what your questions are about longlining, whether it be the types of rod holders or the positions to place them, kinds of rods, what kinds of GPS, whether youre buying a trolling motor or depth finder and want recommendations, or whatever. Then after getting rigged learn how deep your jigs run and bring back more questions if necessary (and you will have 'em) and I'm sure you'll get all the answers you'll need. And good luck with longlining. Youre gonna LOVE it!
Health nuts are going to feel stupid someday, lying in hospitals dying of nothing.