Bob Wells literally wrote the book on cheap RV living: How to Live in a Car, Van or RV–And Get Out of Debt, Travel and Find True Freedom. Both the kindle and paperback editions are inexpensive and the kindle edition has the most liberal licensing available: text to speech enabled, lending enabled, etc. The kindle version is free to borrow through Kindle Unlimited, which comes as a freebie with Amazon Prime. Authors do get paid when people read for free with KU.1)
Will Prowse has written a popular intro to solar power: Mobile Solar Power Made Easy!
secessus recommends Sunny Skye's Sunny Skye's RV Boondocking Basics: Living Well on the Road Less Graveled.
Vanabode: happily camp, travel and live forever on $20 a day - “This is a basic guide, but due to the author's way of thinking, it is more a guide to living very basically in a van. No details on power generation, plumbing or gas / stove.”4)
Brenda Curtiss' How to Set Up & Comfortably Camp or Live in Your Vehicle or Van! (Also Includes Tenting Info)6) although her website seems to be down. The book listing can be seen on archive.org's mirror.
TEN CONSECUTIVE YEARS LIVING IN CARS: Living, Traveling, Camping, Attending College and Performing Surveillance in Cars - “ like this. Oh it does read a bit crazy, as he has some paranoid views about governments, but the information is there, by some one who obviously know his stuff. [Definately] good for a car dweller.”7)
The Tiniest Mansion - How To Live In Luxury on the Side of the Road in an RV - “This is a not bad guide to living in vans. It isn't though so much about luxury. More about practical every day living. I'd [recommend] this one if you must buy any book on living in a van.”8)
The Girls Guide to Homelessness - “supposedly the story of a girl who found herself living in a travel trailer in a Walmart parking lot. But it turns out there was maybe a chapter's worth of practical details about living in the trailer, and the rest of the book is about falling in love with some dude online.”9)
Car Living: How to Make It a Successful, Sane, Safe Experience - “This was a bit out of date, and the tips were not that great. She tackles it more from the [psychological] point of view, talking about social stigma. There was nill information about how to keep warm. Nor was there any details on how to use inverters etc.”10)