I won't address exactly which chain to use because, like everything else made today, I assume there are different grades and qualities.
The inside diameter size of all my chain links is 1"x 5/16"; each link is 3/16" dia. Seem like a 5 foot length is usually long enough but it's a good idea to carry a short extension and a quick link.
You can bolt the chain on one side. Always be consistent with which side of your stands that the chain is permanent and which side the hook is on. Doing so will standardize your climbing and hanging scheme. I always climb with the plan that I'll hang the stand on my left. I cut my teeth using Screaming Eagle stands and they have their hook on the right side (when viewed facing the tree). Which side you choose doesn't really matter but keeping them consistent from stand to stand is a good idea.
I like a rigid hook, instead of a floppy link like some of the cheaper stands use. The rigid hook is easier to hook the chain on. There's lots of hook styles on the market. I like a "J" shaped hook that's welded onto the stand frame. You can easily make a "J" hook from another link of chain...might want to use a heavier chain link for that, just make sure that it's dia will accommodate hooking the chain onto it.
Keep in mind with the hook that the deeper the throat of the "J" the more critical it will be for hooking and unhooking the chain. Some species of tree grow extremely fast and you might be surprised at how quickly (one growing season) a chain will be so tight that it's almost impossible to unhook. A deep hook means that you'll need more chain slack to get the link over the end of the hook. Just a slight "J" seems to do the job on most sized trees. A huge diameter tree will pull the chain on a wider angle in relation to the hook so just be aware.
For actual hanging, here's what I've done for decades.
Tie on a permanent haul line and attach it up near the seat. Doing that will keep the stand oriented as you pull it up. If you tie to the platform, you may have to fight with getting the stand in the pre-hang position.
The tag-end on that haul line should have a loop tied in it which will be used to temporarily hold the stand from a hook to free up your hands.
When I get to height, I install the temp hook on the tree. There are a ton of options for that. A bolt, cup hook, gear hanging strap (with a bow hanger on it) will all work well. I pull the stand up and hook the haul line loop on that hanger in the position that I want that stand. Now my hands are free. Don't try to hold the stand with one hand while you try to manage the chain with the other. Sometimes you can get away with holding it and sometimes you can't. Sometimes it's hard to predict how difficult/easy it will be to set a stand on a particular tree. Seems like a bump, or knot, branch, lean, etc will surprise you making it difficult to get a firm set. Having hands free is easier and safer.
And I have to mention, if you aren't hanging stands with a saddle and tethered (instead of using the lineman's belt) you are missing the boat. With a tether, you can sit back and rest if need be, prune, scrutinize the position, etc. And the tether will be up above and out of the way. The lineman's belt is ALWAYS in the way of where the stand will set on the tree. I can't stress enough how much easier it is to hang stands while tethered.
Okay, you are at height, relaxed in your saddle and the stand is temporarily hung by the haul line loop from the temp hook.
It's not mandatory, but I usually have a short bungee cord that I hook thru the chain and stretch around the back of the tree and hook onto the stand somewhere near the stand hook. This helps keep sag and slop out of the chain during the process of actually hooking the chain to the stand. It's just one small step to make the process as easy as we can.
Here's where you'll have to make a decision on which link is the best link. A taught chain is okay but remember that you need to remove it someday. We hung stands in Iowa one March and when we finished our hunt in November, one tree species grew so much that we had much difficulty getting the chains unhooked. That's a good reason to use a bolt to attach the chain to the stand...easier to remove a tight chain.
The next step is to actually "set" the stand. 1st thing is to unhook the haul line from the temp hook. At this point, without a bungee the stand could slip depending on the shape and bark of the tree. The bungee keeps everything in place when you unhook the haul line.
Next...double check your tether, reposition it if need be, remove slack, etc and care full step down onto the platform and make sure that all contact points are set against the tree. At that point, give a firm "stomp" near the back of the platform as close to the tree as you can. The stand should be firm and in place.
You can add an additional strap near the bottom for extra security. and eliminate a kick-out if you were to apply side pressure. But do not attach the strap until the stand is completely set. If you put the strap on and snug it during the initial "set" procedure, that strap will interfere with to stand firmly setting the chain tight. Set the stand 1st, THEN attach a secondary strap if desired. The strap only need to be snug, not overly tight. You aren't intending on it to take load, only to prevent kick out from side pressure. Load is to be taken by the upper connection (chain). If the strap is set too tight, and done so before the initial "set", the strap can actually prevent the stand from achieving a tight set.
Now, with all of that said, I've started swapping out chains on some of my stands with Amsteel daisy chains and using a trucker's hitch. It's a few pounds lighter, quieter, and actually easier to get a tight set.
Even though I've never experienced rodent chewing to Amsteel, it's still not metal. Can UV weaken it? Can a stand saboteur cut it? Not certain, judge for yourself and make your own decisions on safety tolerances.