There are some. Dave Galley has some written from a highcoach perspective. Means most of his solutions are expensive. Then ther's the Converting on a Shoestring.
I need to add links. Hsrd to do on the tablet. I will edit this post on the desktop to include links...
Ahhh. A keyboard makes a big difference. I think I need to get one for the tablet!
First and foremost
READ THE POOP SHEETS! Copy the whole mess, even the parts that you think you don't need, onto a CD or flash drive or what ever storage method you prefer. You may want to print out the whole thing (requires LOTS of paper... and Yes I did... all of it... easier to make notes). The original website is dead and gone. It will help you to plan how you will use your conversion, what you need and what to expect.
BNO Articles of Interest written from the perspective of a highway coach conversion. I suggest that you read all of them. (click on the little red button on the left hand side of the page)
Dave Galey's Books. I would suggest the Bus Converters Bible. Just ignore the slide out section where he suggests using cabinet drawer slides stacked. As a former cabinet builder/installer.... that won't work. We used to have the Bible and The Joys of Busing.
Coach Conversion Central Articles Lots of helpful info. Fred Hobe has several articles here. He is a pro coach converter in FL.
CCC's Links page is something you should check out as well. Some links are dead. You know how it is with the internet.