Introduction to Machine Learning Just what the heck is machine learning and how can I use it to get systems to improve their performance/become less dumb over time?
Machine Learning Wikipedia page
All the skinny on machine learning. Start here to figure out what these words mean side-by-side, but quickly step away again before your eyes start to glaze over. You'll get a nicer intro in the subsequent links.
Machine Learning at Coursera
This is Coursera's machine learning course. Taught by Andrew Ng (who is awesome), it is a really nice detailed introduction to the field. If you have it in you to do an entire course, this is a great one to start with.
Andrew Moore's Machine Learning Tutorials
Andrew Moore made an incredible series of lectures on a range of machine learning topics back in the early 2000s. These are real gems for anyone trying to understand the foundations of machine learning and the various approaches in common use today. These have not been updated so some of the fanciest recent approaches are not here, but the lectures are still my favorite resource for most of this stuff.