There are a couple of good sites with info, depends a bit of what you want: mono-rail or field, metal or wood.
I am in the pocess of getting the parts and tools together for a wooden field, my Shen Hao HZX45-IIA as a starting point.
Still have not decided jet on the final shape, it might become a Chamonix/Shen Hao PTB54 aswell.
If I can get enough wood together here in Brazil it will be both, each in a diferent kind of tropical hard-wood.
User barryjyoung here on APUG has made a book about building LF Cameras. I was on the verge of trying out to make a camera, but I am short on both time and money but send him a pm, he's a friendly guy.
“Do your work, then step back. The only path to serenity.” - Lao Tzu