I have recently moved but at my last house I had the builder construct a raised bed garden out of concrete similar to a house foundation. You can see my
raised bed garden on this post. It also contains some other useful links on raised bed gardening.
At my new house I plan to take a different approach. I found a supplier who sells
raised bed kits made from cedar that appear to be easy to assemble. They are not cheap but it would cost you just as much to buy just the cedar so I believe they are a good value. I'd love to hear from anyone who has used these.
Good luck with your raised beds - I think you'll love them.