Simple shockwaves are best understood starting with (quasi) one-dimensional flow -- flow in a tube. The quasi allows the area of the tube to vary so long as the variation isn't so rapid that the non-axial components of velocity become very important or the variation of properties across the tube become important.
Rocket nozzles (and jet engines) are a great example where quasi 1D flow assumptions are extremely useful.
Any book, course, or set of notes entitled 'Gas Dynamics' should be a good introduction to one-dimensional compressible flow including shocks. One popular text is by James John.
Next, you'll be interested in 2D flow -- there the oblique shock (and conical shocks in 2D axisymmetric flow) come into play. These are also very simple -- you will also learn about expansion fans at this point. This kind of flow is ideal for understanding diamond-shaped supersonic airfoils.
Most aerodynamics books will cover this kind of flow. It would typically be covered in a second course in aerodynamics in a university (so you're looking at the second half of the book).
A great resource that can't be skipped is NACA TR-1135 contains all the formulas and charts you could want for elementary compressible flows. A lot of the textbooks will be dedicated to deriving, explaining, and duplicating what you'll find in 1135.
Once the surfaces are curved -- and/or you are dealing with flow that is not solidly supersonic (i.e. you're in the transonic region). Then the flow becomes much more complex and there aren't any simple answers anymore. I would encourage you to check out Bill Mason's (RIP) notes as a nice overview on the application of transonic flow to airplanes.
Unfortunately, I have a feeling that these kinds of flows (with shocks balanced on the top of a transonic airfoil) are what you are interested in. These are extremely challenging to analyze and design. Fortunately, having a general idea what is going on is much more achievable.