If you don't mind straining through the maths, there are a few undergraduate books available (a search on PPRuNe will locate the usual ones as this question comes up from time to time).
If you prefer a less intimidating approach, there are several nil or low maths books around .. one which comes to mind is (memory could be a bit off the mark as I don't have access to it now) H. H. Grover (or Glover ?) .. quite dated now but it was quite suitable for the pilot who wanted a bit more detail than might come from the typical airline conversion course.
Otherwise, a good source is to find a couple of AFMs and work through the examples.
Most of us who work in the area, or have done so, either came up through a mentored airline environment .. or learnt on the run using the above sources to get to the detail ...