I've heard that Redwood is particularly good for outdoor furniture, but I'm a little concerned that the soft wood wouldn't suit some of the structures I want to incorporate into the design. Below is an ASCII sketch of the table design. I've omitted the diagonal bracing I intend to use on the back of the upper shelf unit and the back of the main body for clarity (and because I could get the diagonals to look good in ASCII ).

I intend the top section (the upper shelf and the supporting beams) to be removeable for easy transportation in the future. I think counterboring holes in the main table's backsplash to fit washered bolts will work for this, but if anyone has better ideas for attaching the upper piecce to the lower firmly and securely, but in a manner that can be easily removed later, I'd like to hear about them.

The tabletop, I think, will by 1/2" or 3/4" plywood with a plastic or masonite surface laminated to the top. Or, I might go with clear plywood with a border perhaps made from molding strips, stained to match the rest of the piece. What I'm hoping is that some of you can make some recommendations about the wood I ought to use for the rest of the project. Any recommendations about the kind of hardware to use for outdoor furniture would be apprecatied too (I'm assuming Stainless Steel bolts, and galvanized nails/screws are the way to go, but I'm a beginner at this...).

The latest Fine Woodworking has an article on a garden bench, with a good discussion of appropriate woods. Partial list from memory (random order): redwood, western red cedar, white oak, and teak. Of course, you can always go the pressure treated route. I don't think you'd have much problem using any of these in your project.