I haven't covered the winches yet, and there are a bunch of different ways to power these things. You need to remember that you are lifting heavy stuff in the air over your head, so care has to be used to assure that the winch is not going to drop a load on you when it's brakes fail. They should technically have a racheting pawl safety, so precede with caution. Once again, this can be as simple or as complex as you want to go. 12 volt truck winches can be used, but remember planetary and spur gear winches can be powered in reverse, dropping the load while worm gear and the cycloidial drive ones cannot. You still need brakes and such on them per osha, but they are much safer

used winches off of a salvaged crane would be amazing, as would air tuggers, or electric hoists. They actually make derrick winches, usually 2 to 4 drum winches, and are found on everything from a yarder to a stand alone unit. With that in mind, the usfs once again has been there, and designed two smaller open source yarders, the bitterroot and the Clearwater. Plans are free and can asked for, they will send them, as I have a copy of each. While the line speeds might be a tad high imo, they could be geared down and would provide wonderful service. The bitterroot one is the smaller of the two, and is based off of a rear end differential. The old pulpwood loaders were also based off of one, and I'm sure someone here has first hand experience, so I'll just leave it at that.
A truck or tractor can be used, as could a few guys pulling on a block and tackle. Often, you can get away with one winch on a smaller setup, using a powered hoist on the load line and manually adjusting the jib when it's off load. A come along it a trifor winch would work, and I often use chainfalls. Chainfalls work by pulling an endless chain in a circle, such then powers a load chain. Because the chains hang down, you can operate them on the ground when they are installed above you (like on a derrick). They make electric and air powered ones too, and their ease of use is very hard to beat. Since the load chain and the pull chain hang down, if used for the hoist function you can operate one handed, guiding the load precisely. Very handy working alone. They are used on every construction site, in very large numbers. The old school ones have two slightly different size pulleys side by side and bolted together, with the chain in an endless loop, with a snatch block and hook on one loop hanging down. As you rotate the pulleys by pulling on the chain, they rotate together and one travels one circumference of chain, while the other travels its circumference in the other way. Since the difference is small, and is halved again by the snatch block, very large mechanical advantages can be achieved. The pulleys have slight friction, which surprisingly holds the load. These are called weston chainfalls, and they work by what's known as the differential pulley, or in other forms the Chinese windlass.
Ignore the pulley right under the top one, they don't usually have them like that. Weston had the patent for the standardized size chain so it would fit in the grooves, bunches of people were trying to get past that, including this pic. But it shows clearly how they are built.