Hi, I really like the Sommerfeld stuff. Several things occur to me. First, the matched sets don't require adjustment other than the first height setting because all the shanks are exactly the same length.
Since you're not supposed to bottom out the shank on a router, you place a half inch, common rubber grommet (supplied with sets) in the bottom of the collet. That way all subsequent bits are seated exactly the same.
Next, notice that the finished side always goes down, so the cuts are all relative to the top or finished side of the work pieces. For this reason, you must make sure all our work pieces are the same thickness. If you are buying big box wood, that's pretty easy to manage, but you have to take care to pick pretty flat pieces, maybe one in 10-20 pieces will pass muster.
The solution is really to buy extra thick stock and mill it down to be straight, flat and just the right thickness. That will require buying wood carefully and/or eventually buying a jointer and planer. These tools may or may not be necessary.
If you mill your wood yourself, you have to use it fairly soon after milling. That process often releases stresses in the wood so it will warp it beyond usability. You should make sure the stock spends a few days in your shop area to aclimatize.
Sommerfeld makes a star shaped EasyJig for setting height on its bits. You turn a dial on the jig to the thickness of the stock, and adjust the height of your bit using the jig. From then on while using the sets, all other bits are the correct height.
They make a red version of this for setting up Freud matched sets. Freud bits are fine, I just prefer Sommerfeld's. Everyone has their preferences on blades and bits.
I went ahead and purchased the entire Sommerfeld video sets, although they are all on YouTube. I like being able to sit down and watch with any stops and starts.
Plywood is a wonderful thing, but there's a whole range of types, ranging from the Chinese stuff you get at the big box stores. Ok for, well, really coarse work. Then there is Baltic Birch, which has 13 layers and no voids between layers. Comes in 5ft square sheets, usually very flat because of all those layers, and cuts with very little splintering. Ply is often used for the body (carcus) of cabinets, and sometimes a nice grade of cheaper ply will do for that purpose.
One thing I suggest you check out soon is pocket screw joinery. It is a really strong and easy, particularly for face frames and squaring up boxes. The Kreg K4 kit is what I use, but there is a later model as well. Use the square headed screws rather then the Phillips heads. Use coarse threads for soft wood, fine threads for hardwoods.
This may be more than you wanted to know for now, and you can do a lot with what you find at the big orange box. Just depends on what you want to make.
Have fun with this. it is very satisfying.
The more I do, the less I accomplish.