Wood – use a circular saw for precise cabinet making

I'd use the 24 tooth blade, but be sure it is a carbide type and sharp. Since all your cuts are end cuts and will be covered with baseboard trim, so getting an ultra smooth cut is not that important. Obviously, you don't want to see any large chips on the cut edge, so do your cuts slowly and smoothly. Save your 48 blade for visible finish cuts on softer wood. If you do plan to do any precise finish work, moldings etc, consider investing in an 80 tooth blade for that type of work. Good Luck.

This isn't an answer, I just have a feeling I'll run up against the character limit for comments. What kind of wood do you have? How will it be finished? What is the basic construction style desired, face frame or Euro? What hinge hardware do you have or want? Is there backing? Solid wood or plywood? What wood working tools do you have available? Are you willing to acquire or rent what you need, within reason? Where will this be used, garage, bedroom, living room? Each implies a different quality of cabinetry. Is it wall mounted or floor standing? How much time are you willing to put in to this? What is you general skill level in woodworking?

You can see there's a lot of factors to consider for an ideal design. You don't really need to answer all of these, but the more you can communicate your expectations, the better an answer you will get. In reality you could end up just screwing together some basic butt joints and have a serviceable box, but it will not exude an aura of quality woodworking. Or it could be a literal work of art. Something in between probably, but where?

Hard to work without plans? How about hard to answer without information? :)