Hello and welcome
I'm one of the major collaborators with Rachel on the tiny home project. I saw your comment on the People page and I'll try to introduce you to our current setup and how best you might be able to contribute.
We currently use a GoogleGroup mailing list to discuss various topics ranging from general project direction to specific discussion on how we might implement certain features of the home. To see past discussions please go to our googlegroup page here. You can also join the mailinglist on that page. Doing so means that you will get an email every time anyone sends a message to the group, and that you will be able to send emails to the entire group by sending an email to firstname.lastname@example.org.(If you want to limit the number of emails you'll receive in a day from the mailinglist you can change that in your settings once you have signed up.)
In addition to the mailing list, we have a blog here which we've been using to collect research and relevant findings. If you understand how to subscribe to RSS feeds, then you can do that with the blog and the feed will update whenever we post something new. If you don't understand how to do that but would like to experiment, please give us a shout on the mailing list.
The wiki is where ideas go once they've been hashed out a bit on the mailing list and in face-to-face discussion. For example, we've recently been having a discussion on the mailing list about various potential alternative energy sources, and once we understand the topic a bit better we'll write up a couple articles on the wiki. We've also been working in various CAD programs to make some simple designs for the house, and images from that work will go up when they are ready.
One place to start looking into the sort of questions we've been asking about the house would be at our Elements of the Home page here on the wiki.
Unfortunately there is a small learning curve before working with the wiki makes sense. The most important thing to keep in mind is that what you type when you are editing the page is not exactly what everyone will see when they view the page. The best thing to do is to press the 'Show Preview' button to see how everything will look once you have saved the page. (It's down underneath the editing box beside the 'Save Page' button). WikiEducator has a good series of tutorials that will walk you through the basics of editing wikis located at www.wikieducator.org/Help:Contents.
When exploring the basics of wiki editing, the best place to make test edits is on your user page. Your user page is www.wikieducator.org/User:Gum and you're welcome to do whatever you want there. My user page is at www.wikieducator.org/User:ScottGeoffrey and a list of interesting user pages is at the User Page Expo if you want to see some examples.
The best place to ask questions would be on the mailing list. Please feel free to ask any questions you might have and we'll do our best to get you an answer as soon as possible.