OpenCv is a great start, and is where I began.

this book: http://shop.oreilly.com/product/9780596516130.do has a number of worked examples that explain things well.

It does touch on Machine Learning, but it focuses much more on the fundamentals of computer vision, like feature detection, that allows things like SLAM to exist.

I have to say that this book: http://shop.oreilly.com/product/9780596516130.do

did a pretty good job of explaining everything for opencv proper.