This site IS one of the greatest resources out there. There are some awesome people here that bring all sorts of experiences and apply it all to one common goal, bus building.
I think the hardest part about building a home inside your giant tuna can, is keeping motivated and not feeling overwhelmed.
I have been using a program called Evernote to gather all of the pictures and text and links and ideas that I won't ever remember. I also use it to break down my bus into smaller, manageable, projects. It's great for finding good prices and remembering them. I also have a Timeline that is a work in progress, and I have a super simple spreadsheet that only has MAJOR GOALS on it. I also use Trimble sketchup (formerly Google sketchup) for all of my planning and building needs. my current sketchup file has four 'bus shells' with various layouts, each of which had changed several times over. I think i'm in revision 6 or 7 now.
Another good resource is to search for 'tiny house' or 'tiny home' then consume video. I do this just to get great ideas on how to save space, build better, build greener, cheaper, etc. "the movement" for better or worse, really has opened up a lot of opportunity in free flowing information and cultural acceptance.
On the subject, I have an expense list. This is a dangerous thing, because you don't want to really feel a "financial burden" that makes it feel impossible. But you should know what your bus is going to cost to build over the span of time you have. also this helps you find your priorities. Maybe an extra month or two is worth waiting to 'finish' if you really have that one item that's essential to your home, but ultimately out of your cost range for your time span. I find myself teetering on this line all the time.
Since you don't have a bus yet, i'll show you where I got mine. It was a relatively good experience.
http://ncschoolbussales.dpi.state.nc.us/
A good rule of thumb that I saw somewhere; if you're building every day full time, it will take roughly three months to complete a tiny house.
I only have weekends, but i get 3 days. So I figured in 6 months, 24 weekends, or 72 days that I can work.
Made a list of major projects, EG: Grind floor pan and bondo holes, Remove stop sign, patch holes, (reinstall?), etc.
Then I started assigning little projects to different days of the weekend, Now i never think "man, what should I do today" then end up wasting a day shopping for parts or whatnot, I can shop at work or other downtime, then have everything I need waiting and ready for my project(s) at the end of the week... Come visit
my thread in a few weeks to see how it's working out.
(EDIT: just so you know, I feel this is a tight schedule for my goals and income, I will be doing almost nothing else until it's completed.)
Hope this information helps your process.
Most importantly, have fun building!