I went to the Build With Chrome site, installed Google Chrome, and built a house. You can use other Browsers but I don't know if they work as well. It's been set up to work best on Chrome. The install was fairly painless and the interface to build with is pretty simple. There aren't a lot of choices for parts, pretty much basic bricks with two types of slopes in 10 colors. I ran out of bricks before I got the roof finished. You get a thousand pieces to start and you build on a 32x32 baseplate. Once you finish you can publish your build and build another. Here's the build page.
The only two other parts available, found under the Extras button, are an old style window and a door. It's pretty easy to get used to the choices as there aren't many. Moving the bricks around isn't too bad. The build can be spun 360 degrees and there's a fair amount of tilt on top of that. You can get you baseplate spinning pretty quickly if you aren't carefull. It didn't look like a I could build on the lot next to me but I just might not have figured out who to do that. I skimmed through the FAQ but didn't see anything about that. I'll spend a bit of time looking and see if I can make something better.