A rather large silver maple tree trunk came down in a wind storm recently. I have cut most of it up for firewood but there was a nice 4 foot section that I decided to make into some boards. Maple has a tendency to rot in the center but this piece was solid.
A few years ago I built an attachment for my chainsaw to let me use it to cut boards from logs. It is based on the Granberg small log chainsaw mill. The Granberg mill is made of aluminum and mine is made of steel so it is a bit heavier but it is used sitting on the log or guide board so it is not too much of a problem being heavier.
To guide the mill for the first cuts a 2X6 is screwed to the log.
The log after the first cut.
It makes cutting the boards a lot easier if the log is squared up first. My saw bar is not long enough to cut through the center without taking the sides off. It took some doing to get the log rolled up onto the 4X4s. A peavey would have made things much easier. 
After the log was squared up I cut it into boards. Here I stopped the cut part way in to take a picture.
The boards now get stacked in the shed for a year to dry.
Does a very nice job