Pretty hard to go past books written by Ron Edwards
"Mud Brick Techniques" published by Rams Skull Press - good little book probably less than $10.
He's also co-written "Mud Brick and Earth Building the Chinese Way"
This is a very good book. I recommend it highly along with the aforementioned Mud Brick Techniques.
Gregory Ah Ket also has written a good mudbrick book.
If you can get a second hand copy of G. F. Middleton
"Build Your House of Earth" so much the better.
Don't overlook the notes/booklet of Brian Woodward- mud brick architect
"Mudbrick Notes" ($15 plus postage).
Here's a hint for a beginner like me.
I like to use two parallel string lines either side of the brick. It's easier
to keep the bricks level this way.