I took a few more pictures of the bathroom vanity for somebody who was curious how it was built. While I was at it, I took the sink and faucet out of their boxes and set them in place, too. :) That's always the fun part.
This last picture probably shows the construction method best. Sorry it's a bit fuzzy. The lower shelf and the counter top surface are both made from left-over 2x6 tongue and groove flooring. The rest of the wood; the posts and rails, are ripped from 2x4s. The posts and rails are all 1 1/2" square, and are held together with pocket screws. You could also mortise and tenon the joints, but we just don't have the time right now, and pocket screws are a simple, square, sturdy joint that takes a neat jig, but not a lot of time.
The flooring pieces were glued together, clamped in place for 24 hours, then cut to length and screwed in place from underneath the rail that supports each flat surface.

I know... not exactly a professional how-to, but I hope it answers your questions, Serina.

Chris