So I have had a really hard time finding decent pages about pullys on the net. Actually that's not true, I had a hard time finding PICTURES with the basic info. Thus I'm putting up my research as I find it. Here are the super simple systems, and then some basic piggy back systems.

Ratio	Image	Blurb
1:1		Super simple. It's really just a redirect and not a pully system at all. Pullys only do work if they travel when you pull the rope. This is a bear hang.
2:1		You have to pull twice as much rope to move the load, but with half the strength.		A 2:1 system with a redirect. Maybe you want to pull down instead of pulling straight up? Redirects can be any angle, I just didn't want ginormous pictures.
3:1		3 to 1, blah blah blah...The second pully is attached to the load, the first to the tree/cable/roof/cloud/etc.		You have to pull 3x the rope...so your 15ft high bear hang now needs 60ft of rope (15x3 + 15 so you can actually reach the end from the ground!). But on the plus side, your 60lbs of food feels like 20.
4:1		The rope doesn't actually have to zig-zag on a different pully every time it goes to the load, you could use a double pully (2 wheels on 1 axle) to save space.		4 single pullys or, 2 doubles.
5:1		I didn't draw the redirect...do you really need it at this point?

Piggy-back Systems

Are we following so far? Well that was the simple stuff, now for a bit harder. Piggy-back systems...well...piggy back. you take 2 simple systems like a 2:1 and a 3:1 and mush them together to get 6:1 (2x3=6). The pictures will help I hope.

Ratio	Image	Blurb
4:1		A 2:1 riding on a 2:1. Pull the red rope and green also moves, but at half speed, the load appears to move at 1/4 speed (if my undeerstanding is correct) ...Please don't quote me yet.		Redirected.
6:1		A 3:1 riding on a 2:1.		I believe That the green rope moves at 1/2 the speed (and distance) of the red rope, and the load at 1/6th. The redirect doen't make a difference (that I do know).