I had 3 sheets of 3/8" plywood left over from our kitchen cabinets, so I used those for the structure. I think 1/2" would have been a bit easier to use (sturdier), but this is what I had. I am going to line the outsides of the cabinets with 3/8" beadboard, so the walls will be 3/4" thick in the end. I started off by cutting the sheets with a circular saw to make ripping them easier:
I ripped the sides and cut them to length:
I also cut the shelves:
I marked the back of the side panels to cut the dadoes to accept the shelves. The "B" indicates the bottom. I always try to mark cabinet parts as much as possible to help avoid errors:
I used my table saw with a dado blade to cut the dadoes. The piece rides on my panel-cutting sled - they get cut on the marks as shown. This is a very easy way to cut the dadoes, but you need to be careful to keep your hand away from the blade.
Here are the shelf pieces sanded and stained (first coat). I have gotten into the habit of staining the pieces of my projects before using any glue on them. Glue makes stain look bad - even the "stainable" kind. It takes a lot effort to fully clean the glue up, so it makes way more sense to just stain things up front. I will also put polycrylic finish on these before assembling, again because its much easier.
I always leave a stir-stick in my stain. I stir it each time I put a rag or brush in it. This may seem excessive, but it keeps the color even. If you have solids in the bottom of the stain can, you can bet you did not get a consistent stain color as you used it up.
I decided to make the side panels look more like planks than solid pieces of plywood. I ran these in my table saw with a plywood blade set to about 1/16" inch - just enough to give a line that would stain darker. I also distressed these with some nails, a hammer and a scraper.
Here are the rails and stiles, dadoed out to attach to the plywood parts. I will blind nail these with my 1/4" crown stapler (18 gage).
The next thing to get these parts stained and sealed.