I smoke chickens on the gas grill on occasion. Tried a turkey breast last week and that took nearly 12 hours, so I don’t know that I’ll be doing that again. And of course the technique with your grill would be different from what I did, since my gas grill doesn’t have any smoker attachment.
Steps which are different on mine from how you’ll do it:
It’s easy to do this on my grill actually: I soak wood chips in water for a bit, then wrap them up into several packets with heavy duty aluminum foil. You can buy dedicated smoker boxes which are cast iron, to hold the chips, but honestly I think the aluminum foil is easier!
Then you remove one grate (typically one off to the side; mine only has two grates). You place a foil pan under the other side, under the grate (this catches drippings, keeping you from having semi-raw animal juices on the floor / patio under the grill, or inside the grill).
You place the foil packets, or smoker box, directly on the flavorizer bars or lava stones, poke a few holes in the foil (the box comes pre-perforated), and then turn the grill on to a low temp - but JUST on that side. Not on the other side.
Then you put the meat on the side without the chips / heat.
Steps which will be the same:
Insert a remote thermometer if you have one (I HIGHLY recommend this) into the meat and set the readout portion of it on the shelf beside the grill. You close the grill lid, and watch for a bit to make sure that the temp is getting into the right range (225-250 or thereabouts).
Then you wait for a few hours. I’ve had a whole chicken (6+ pounds) take 5-6 hours. Open the grill as seldom as possible - I do typically every 2 hours or so to replace the woodchip packets.
Recipes: Well, there are TONS of dry-rub recipes out there. Marinating / brining is also a very tasty thing to do to the meat before you plunk it on the grill/smoker. So I don’t have anything specific for ya.