The Mind Illuminated: A Complete Meditation Guide Integrating Buddhist Wisdom and Brain Science for Greater Mindfulness
It feels weird to review a meditation book, because each set of techniques assumes a starting place (where the techniques are most helpful), and has a intended and desired outcome. As with many meditation guides, the outcome is a bit nebulous, but the guide and techniques are exceedingly clear. John Yates (also known as Culadasa) outlines a very specific meditation path, with very clear stages and explanations, based on breath-attending awareness and concentration.
The clarity and specificity is wonderful. The technique itself, and intended outcome, did not become my own meditation path, but I took several concepts from TMI that were useful. The book has helped many people, so if such a clear path is interesting to you, I'd recommend at least starting these practices.