For what it is worth, as I see it, there at lest three major components to knowing what you are doing in applying machine learning:
- Understanding the mathematics behind it.
- Understanding the tools for implementing it.
- Understanding the domain in which you are applying it.
If you are mathematically mature, I would recommend working through The Elements of Statistical Machine Learning and learning R, if you don't already know it. If you are not, you might want to check-out the Handbook of Statistical Analysis and Data Mining Applications, instead of TEoSML. That will get you two-thirds of the way to a basic skill-set, fast.
There are some caveats, though. if you are interested in being some areas of commercial work, you might want to learn SAS programming, or some other language/platform, instead.