Based around the 37 bodhi-pakkhiya-dhammā or "Wings to Awakening," of which the work is named, with essays providing a basis for understanding the components within the wider framework, and related translations so the reader can make up ones own mind on what they are saying.
The Essays give context to the selected translations, although it could be argued that this is a philosophic work it is an excellent read, easily digested, providing a basis for practice as-well as investigation, and doesn't have to be read systematically as each of the three sections can lead on from and on to the others just as easily as they do in the current order.
I chose to read this from page one, systematically through the book and later I may decide to read it in another order or just by chapter, either way I decide to read this work in the future it has provided topics to learn more about which one may not associate with the practice and teachings of the Buddha, such as music theory and cosmology, so I can understand the context of the teachings of the Buddha better for myself within a framework faced in everyday life. the interconnection with other fields shows just how the Buddha used all situations to reflect on practice, and tune his own practice to better connect with the true dhamma.
Wings to Awakening is certainly a good book to use to reflect on the teachings of the Buddha
The PDF is easily available on Access to Insight, however, hard-copy books can be difficult to get hold of.