IMHO, "Naked Statistics: Stripping the Dread from the Data" by Charles Wheelan is the best book to start with Probability and Statistics(you can buy it using the link below). I've studied those fields when I was at Uni, but never really got the intuition right. I wish I would have read that book back then. The book is short(~200 pages), and focuses on providing both the context and the intuition behind Probabilities. Once you get that right, the formulas just make sense. After reading that book, you will be way more comfortable to read books about Machine Learning, or any other fields where Probabilities and Statistics are a prerequisite.

http://www.amazon.com/Naked-Statistics-Stripping-Dread-Data-...

https://www.coursera.org/course/hciucsd

https://www.coursera.org/course/design

http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/032134...

And, finally, if you want to do some usability experiments and testing:

http://www.amazon.com/Handbook-Usability-Testing-Conduct-Eff...

http://www.amazon.com/Naked-Statistics-Stripping-Dread-Data/...