From my experience...
Okay. No two traditional archers are the same. Once you get that figured out, you can have a lot of fun with it.
DEFINITELY GET A BOW STRINGER. I can't stress that enough. It's a safety factor as well as it will protect your bow's limbs from twisting.
I shoot split finger. I shoot what we call instinctive. I do not use a sighting method. Saying I don't use a sighting method does not mean I don't aim. I aim by practicing my form and with a consistant point, draw, anchor and release I am able to condition my shooting to account for different distances. Like shooting a basketball or throwing either a baseball or football. Takes a lot of practice. This is part of the enjoyment of traditional archery.
Shooting off the shelf and shooting off a rest both have their advantages and disadvantages. If you plan to shoot 3 under and gap your shots or use the point of your arrow to aim, shooting off a rest, I believe, would be the best option. This will allow you to use vanes, though feathers are recommended, as well as shoot with your bow in a more vertical position. This can be and usually is a more accurate shooting method than shooting instinctive. I've found that switching from or just experimenting with traditional when you've got a good experience base with compounds, this method used with a recurve bow, is a fairly easy transition. I've also found that these folks are fairly accurate starting out. Yet, I've also seen them reach a "flat" spot where their shooting accuracy will drop for a short period, then they'll go back up to a more accurate shot. Sort of like body building. First you lose weight, then you gain it back in a better quality of weight.
Shooting off the shelf, you can use a few different options. You can use velcro, calf hair, bear hair, even a leather tab. I use a leather tab. The hair and velcro will enhance how quiet your draw is. I would recommend this if you are shooting alluminum or carbon. I shoot wood arrows so the leather tab is adequate. Some folks believe, and I'm not going to argue against it, that using the hair or velcro will aid in the speed of the arrow. If you shoot off the shelf you will need to use feathers, aluminum, carbon or wood, you need to use feathers. The feathers will collapse and allow a cleaner launch off the shelf. This is more critical with a longbow than a recurve as the longbow is not cut to center to the degree that the recurve is. The longbow, for this reason, requires a little more cant. This serves two purposes. One, it opens up your sight window and second, it assists in keeping your arrow on the shelf through the shot. If you're right handed that translats to holding your bow canted with the top tip between the 1 and 2:00 position and the lower limb between the 7 and 8:00 position.
Whichever you choose to go with, I'm sure you'll have fun with it. Don't be alarmed if you've been shooting strictly recurve for a few days to hear your compound more acutely. There are fewer working parts, therefore less parts to make noise. I understand the compound manufacturers are getting better in this arena, which is good. You'll also notice with the recurve or longbow a lot of arrow "wobble" when you shoot. This is called the paradox. It is caused by the arrow bending around the bow. For this reason, the spine of your arrows is critical for quality arrow flight. The bow will shoot slower than the compound. Another reason to maintain your form through arrow impact.
When I'm working with my kids, I constantly remind them to keep their bow arm locked pointing at the target as if they were pointing their finger at an object.
If you're eye dominance is in opposition to your shooting arm, you can still make it work, however, many will recommed you shoot off your dominant eye's side. I'm left eyed and right handed. I shoot right handed and do fairly well as long as I can keep up a good practice routine. However, I can shoot left handed with a lighter weight bow almost as accurately with little or no practice.
I think I'm getting too much into it. I'll just answer questions, probably be easier that way. I really enjoy traditional archery. My compound shooting was less than mediocre and because of this I was at the point of giving up bowhunting. A buddy recommended I try a recurve just for the fun of it. I fell in love. I shortly went to shooting a longbow and though I have one of the best recurves made, I rarely shoot it as the longbow has my archery bone in a vice. Just love shooting my longbow.
Like I said, no two traditional archers are the same, therefore, don't hold what I tell you as "law" till you try and prove it yourself. Others may and will have different methods that can help you where my methods won't. You'll see. Hope you enjoy it the way I have. And above all, as with the compound, PICK A SPOT. "Aim small, miss small". The pick a spot advice can't be expressed enough.