Lifting roundwood posts without power equipment

This may be a dumb question but how does one go about lifting posts into place without the use of a crane/power equipment? We have started the arduous task of removing 12 trees to create a firebreak between us and the next property and we are planning on using these trees as posts in our new home. They are all 20 ft plus and we are, so far, moving them through the woods to the house site with a come-along and ropes. There is no way to get a vehicle in to either site. We don't have a generator or electricity in either area. I haven't played around with pulleys much, but it seems that there should be some system already in place that would work for us.

Look up "gin pole" on YouTube. There are dozens of vids. I've raised several large barns 2 stories tall by myself using ramps, levers, jacks, pulleys, and gin poles. It's really quite simple.
As for moving logs thru the woods, see if any locals have horses. They are a whole lot less work than what it sounds like you are doing.

There are several manual methods you could use, depending partly on exactly what you want to raise. A gin pole as Jim says is good - here is a very thorough description of the process with things to be aware of as you work: I’ll take a Gin Pole, straight up.

If you just want to set posts into the ground, a tripod made from sturdy saplings with a block & tackle sized for the load (the gin pole article leads to a link for this), or your come-alongs, might work best.

Note that the block & tackle article has some intimidating-looking math, but the basic facts are pretty simple and diagrammed. You need to have a good idea of how heavy the posts are.

Check out this video starting at 3:30

These guys just assemble the frame sets first on the ground, and then just push them up.  Once vertical, they then lift them up on to the stone pedestals, and then nail in supports to hold them vertical.

From 1:45 onwards

A few years ago here at wheaton labs