I was reading through the instructions from the Pridle 18-19 manual for setting up the mainsheet blocks. However, there seems to by a type-O (one of many) in the instructions. It says to put the rope through the same pulley twice (steps 3 & 5 of the Prindle 18 special instructions). I don't imagine this is correct for two reasons, 1. logic, and 2. the picture shows different. Am I just crazy, or is this an error?

What would be most helpful to me (as a new sailor) would be pics and/or instructions on how to run the ropes through a 7:1 system correctly. I've tried some trial and error, but it's hard to say, "ya, that's right," when you're not sure what "ya, that's right," looks like!

Thank you.

You're right there's a typo step 3) should read: "Towards you through middle roller of upper block."
Pretty straightforward really, lay the blocks on their side, with the camcleat of the single ratchet block towards you the follow the instructions in the manual.
I've numbered the steps in the following two pictures.



Here's a link to a useful page from harken, I haven't found instructions for reeving your system there, but a nice source of info nevertheless:
http://www.harken.com/rigtips/rigtips.php

here's the second picture:



I've got a different mainsheet steup from yous so pics of mine wouldn't be useful.
How did you do last weekend?

This one works better for me, I found it somewhere on this forum:

In the previous setup, the sheet tension increases/ decreases progressively from on side to the other as you ease/pull. You can see something similar with the speed of each section of the line. On the setup suggested here, things are more even (or better "centered"). On light winds and if you have some friction on your system, you might notice this setup running much smoother.

(edited: the "inversely proportional" part was not true...)