This is the ratchet block I have for the mainsheet. The purchase is 4:1 wich has always been sufficient. The end of the sheet would normally terminate on a becket. Mine ends on a stopper knot on the extra sheave on the block. I can take this line and connect it the the end of the boom for 5:1 or I can take the end and connect it to a line leading to the tiller for sheet to tiller steering, but typically I have found it more effective to tie a line to the mainsheet above the block or right to the boom in lighter conditions.
In this photo you can also see one of the cam cleats fro the continuous traveler line, a spinaker sheet block on the aft end of the coaming, and a padeye on the bulkhead under the traveler with a clip attached. The clip is the tether to my son's harness. There is another padeye on the starboard side and one under the companionway.
Rigging Page
Traveler Page
Backstay Adjuster
View of the cockpit