
A balanced introduction to machine learning principles and applications. From the cover: "Case studies and algorithms to get you started".
Conway & Miles - Machine Learning for Hackers: Case Studies and Algorithms to Get You Started
Once you read and understood this, I'd do an online course...
Ultimately, ML is a mathematical discipline. You can ask for a gentle approach that gets you to the foot of the mountain, but "if you want to learn about nature, to appreciate nature, it is necessary to understand the language that she speaks in." If you want to be more than an amateur, there's not much substitute for getting comfortable with math at the level of, say, Kevin Murphy's book.
The good news is that the required math is fairly elementary - calculus, linear algebra, probability and statistics, all freshmen or maybe sophomore-level topics - so it shouldn't be beyond reach of a motivated developer able to set aside some time to learn. MOOCs and organizing study groups with friends/co-workers can help a lot here as well.
Steve Jobs - Walter Isaacson
Artificial Life - Steven Levy
On Writing - Stephen King
Machine Learning for Hackers - Drew Conway and John Myles White
How Doctors Think - Jerome Goopman
Cholesterol Clarity: What The HDL Is Wrong With My Numbers? - Jimmy Moore & Eric C. Westman
Barbarians at the Gate: The Fall of RJR Nabisco - Bryan Burrough & John Helyar
http://shop.oreilly.com/product/0636920018483.do http://www.amazon.com/Machine-Learning-for-Hackers-ebook/dp/...
It's definitely a practical approach. There's a lot of explanation but, despite coming from two PhD candidates, it certainly did not read like an academic paper.
It's also case study based, not necessarily algorithm based.
As a bonus, I used that book to teach myself R. I don't think it's meant to be an intro to R tutorial, but it worked for me.
All three are positives in my book.