I have been a big fan of the website cheaprvliving.com for a long time now. It is full of really useful information from Vandwellers and Fulltimers who have been living the alternative, mobile lifestyle for a long time, in everything from minivans to school buses. I really appreciate the no-frills attitude of the site and the vans/RVs/camper conversions that they feature. They have simple ideas about simple living.
I just recently discovered that cheaprvliving.com launched a sister site, called Cheap GREEN RV Living, and it's all about how to live more sustainably in a camper, bus, converted van, or car. There are lots of ideas for off-grid alternative energy systems, boondocking tips and tricks, and how to respect the planet while living more freely. Some of the articles on CheapGreenRVLiving.com talk about how to pare down your possessions, some talk about the logistics of using the toilet, and others give detailed step by step instructions for installing a PV system on your van's roof. My favorite page is the product reviews page. This guy is super honest and has actually used all of the products he reviews, so I found this article really useful.
Anyway, check out both sites if you haven't already, you won't be disappointed!