Hi Frances - just a few tips from my own experience:

1) Don't be afraid to build it big. Others may have the opinion that small equals manageable, and while that's true, it also places limitations on what could be the most treasured piece of your property. My family spend a LOT of time in the potager. My wife and I tending plants, or relaxing, the kids eating them or playing or whatever. It is easily the most heavily utilized part of the yard - by far. So I maintain that it makes sense to build it at least somewhat bigger than you might currently envision. Mine is about 36' x 40'. Ideally, I'd like it to be at least 60' x 60', but physical site limitations make that impossible. Now that may be waaaaaaay bigger than you are thinking, but my point is this... whatever size you currently have in mind, I would recommend you increase it by at least 50%. You won't regret it.

2) Make decisions about what materials to use for enclosure, paths, and bed frames. Many people on this forum use picket style fencing, but you can use whatever suits your taste and pocketbook. Again, my recommendation would be don't skimp. If we ever move again, my next potager enclosure will be a 2-foot slipform masonry wall topped with 2-foot black metal fence. This won't be cheap by any means, but again, given that the potager is the focal point of our yard, it will be worth it. Play with fence arrangements to maximize square footage, and keep in mind the square footage that a few extra fence panels will give you. For example, assume that an 8-foot fence panel costs $50. You can use 8 panels to make a 16' x 16' enclosure (256 sqft). Or, if you buy just 2 more panels, you can make a 384 sqft enclosure (16' x 24'). 50% more space, but only 25% more cost. You mention framing the backyard in low fruit bushes - if these will grow dense enough to form a hedge, then that is a great option for an enclosure as well.

3) Think about what you want to use for bed frame material. The two most common options are wood, or some kind of masonry. I used 1" x 8" x 16" pavers, turned on edge. I like the look, and they are very durable. At 1$ each, they were also pretty cheap. 24 pavers ($24) yields a 4' x 12' bed, the perfect sized bed for a potager, IMHO.

4) Think about what you want to use for permanent paths. You could use grass, or wood chips/bark mulch, or pavers, or crushed stone, or whatever else you have available.

I guess my overall point is - dream big. There will be a LOT of work and cost at the front end of the process, but it will be worth it. Concentrate on the hardscape in the first year - enclosure, beds, and paths. The plants will come later. Subsequent years will be very little work and expense. I feel strongly that a big, productive kitchen garden is not only a good hobby, but it is a great way to beautify your property, provide healthy food and activity for your family, as well as a place to socialize and relax. It's worth...

I can sympathize! For some strange reason, I keep attempting to run a potager in Texas and there is little information down here either.

Here's some ideas:
1. get a garden book for your area and make a list of annual flowers they recommend for spring, summer, and fall.
2. go to the square foot gardening forum, or either square foot gardening site and figure out what space you need for the veggies you want (http://www.squarefootgardening.com/
and http://journeytoforever.org/garden_sqft.html)
3. Each of our states over here has an agricultural extension agency with online publications. For example, here's oregon's site which is probably close to your climate: http://extension.oregonstate.edu/deschutes/Horticulture/GardenPublications_000.php.
4. Once you have an idea of what you want and the space you need, THEN design your potager

Hope that helps!

Thanks!

I don't think I want to increase by 50%, tho! I've ear marked an area that's about 16 X 16 meters (about 53' on each side) and it will be somewhat in the shape of a triangle with the long side out towards the terrace/house. I think we will put an English style greenhouse in the center corner and put a path from it to the terrace. I doubt I will fence the area since it is off center on our property (all the way to one side) and there is a small stream going down do a lake farther out on the property that would get in the way--it would also break up the view more than I want.

We are looking at the idea of either pavers (turned on the side, as you mention), natural stone, or wood.

I agree also that I need to look at what we want/can grow to help with the design. I'm working on that part now. It is just really easy to feel overwhelmed and I cannot find any books to help me out here. I guess I'll need to hit amazon soon

Here's a link for you that may be helpful. She writes of long days, but short growing season in Normandy
http://www.frenchgardening.com/postcard.tmpl?SKU=3205196331175837

Here is a good list of short season growing vegetables for you:
http://www.coopext.colostate.edu/4DMG/VegFruit/local.htm

GGG