The Joy of x

Mathematical education is in dire straits - this is a fact. But this book is not something I'd recommend for people who have always struggled to get into Math or for people who were good at Math but didn't necessarily like it.
The very issue with trying to please everyone is you end up pleasing no one. This book overextends itself in trying to court the seasoned amateur and the professional, not to mention trying to help people who loathe the field. Spoon-feeding the latter the absolute basics (what is multiplication, what is a circle, etc.) would hardly work as the basics are also the most tedious part of Math.
Paul Lockhart puts it aptly when he suggests that Math education needs to be fixed down-to-top - giving students time to come up with proofs by themselves and not simply giving them the absolute basics through flowery details. This is my opinion, of course, and if more people are interested in Maths because of this, then it's all the better - this is not how I would recommend starting your journey.
This is a breeze, so you could quickly finish this throughout a single afternoon. I'd recommend this if you have free time to whittle away, doubly if you're even slightly interested in the field.