But to answer the question you asked, you need a 2x4 or 2x6 that is as long as your longest log. You are going to use that as guide for your cut. align the edge of the 2x6 with the edge of the log where you want to cut. Using long wood screws attach the 2x6 to the log so that you are using the edge of the 2x6 as a guide against the fence of your saw. You don't want to cut the 2x6 just use it as a guide between the saw and the fence with the edge of the log in line with the saw blade. Now make your cut and you have a flat surface. Rotate the log 90 deg. and move the 2 x 6 so that it is guiding the new cut and make the cut. Now you have a flat surface that the log will rest on and a flat surface that you can use to rip the log as you wish.If you're using a table saw you're going to be limited by how much of the blade sticks above the table. If you've got a band saw you can probably cut a bigger log but you'll have to go slower. The chain saw saw mills waste a lot of wood. Each time you cut you are removing 1/4" of wood and making a rough cut so you loose more wood smoothing it down. But the chainsaw method will let you cut up some much bigger logs. Look at the third video down. http://www.hud-son.com/Boardmastervideo.htmIf you look on the local Craigs list you might find someone who has a portable bandsaw mill will come and help you cut it.