This book completely saved my life my first semester of college. I failed to pay attention in my psych stats (#freshmanyearsucks) but with the help of this book, I was able not only to catch up, but also get nothing but As throughout the remaining semester. Granted I ended up with a C+, but I pulled it up after getting a solid F on the midterm.
It's readable, understandable and starts from the ground up. Plenty of practice problems and clearly formatted in a way that even someone who abhors math can understand it if they work at it.