I am planning on 2 beds......4x10 each to start. I'd like to have tomatoes, squash, cukes, cantaloupe. Problem is the 3 of those are crawling plants and I'd need to have a trellis of some sort.
Did you guys use treated wood for the boxes? I don't have access to cedar boards.
Like the OP, my land is mostly wooded too so I'm limited to where I can put in a garden. I wanted to plow up the sunny front yard for a garden, but my better half kind of frowned on that idea. So, I went with raised beds in the side yard instead.
I used cedar/fir 4x4s for the corner posts on all of the beds that I built. On my first 3 beds I used untreated pine for the sides and coated it with linseed oil. That was strictly a budgetary decision at the time - I was broke that year!

Those beds were 4x8 and 12" tall. I spaced them 4' apart so I could get the mower that I was using at the time between them. Plus the 4' allows a lot of "working space" between the beds. Last year I put in another 4x8 and two 4x12s. I placed the 4x8 in line with the first three that I built and the two 4x12s perpendicular to them keeping the 4' spacing. Last years beds were all cedar.
With regards to using pressure treated - I've read conflicting things on that. Some people say absolutely not and others say that the chances of any harmful chemicals leaching into the beds was pretty slim. I opted to stay away from the pressure treated as I'm trying to be as organic as possible. I was able to find the fir corner posts at Home Depot. I was able to find cedar lumber at a local lumber yard but last year a new Menards opened up by us and they carry a good selection of cedar lumber. It was about 40% less than the local yard so I bought it there. If all you have is Lowes or Home Depot in your area you might have trouble finding cedar there.
I brought in dirt from a local place that does topsoil and mulch. I bought their "Gardener's Special" soil that was a mix of topsoil and mulch. I haven't been able to get much of anything to grow in it! One of my plans this week is to send out some soil samples for testing so I know what I have.
You mentioned the vining plants you're planning on planting. I used tomato cages last year for cucumbers and zucchini. That worked pretty well. Use Youtube and you'll find lots of examples of people doing this.
On last suggestion - I wanted to put in "a real garden", but as mentioned, I didn't have the space for it. I put an ad on Craigslist looking for garden space and got a reply from a guy that's about 1.5 miles from me. We're still waiting for the weather to break in order to get together, but I'm hopeful we can work something out. His 13 acre property is more farmland than mine is and he already has a 40'x160' garden plowed there. He's going to give me part of that space and we might also share some of the space to put in stuff like pumpkins, watermelons, etc. You might also want to check with any of the local municipalities around you to see if any of them have "community gardens." The suburb I used to live in have plots for rent (about $30 for the season).
Happy gardening!!