Question: I'm new to C++ and am wondering how much time I should invest in learning how to implement template classes. Are they widely used in industry, or is this something I should move through quickly?

Answer: 
At my employer, the **main** thing we use that's in C++ and not in C is indeed generics, AKA "templates". Inheritance &c are nice (but with pluses and minuses), but templates are *absolutely crucial* -- **the** main, cost-less advantage of C++ over plain C. Master them, you **won't** be wasting time!-)
As others have noted, Templates are a very important part of the C++ language. In fact, they're a turing-complete language themselves ;)
However, not only does the STL make heavy use of templates (ever used std::vector or std::pair?), lots of other libraries do, too... the most notable is probably boost. I hope that gives you an impression on how important they are.

What you should definitely learn is how to use them in the context of classes and functions. When you mastered that, you can move on to more advanced topics like template specialization or template-template parameters. 
And if you still haven't got enough of templates, you can check out
"C++ Templates: The Complete Guide" by Nicolai M. Josuttis and 
"Modern C++ Design" by Andrei Alexandrescu. Even though the latter is really a hard piece to understand.

For a start, this resource <http://www.parashift.com/c++-faq-lite/templates.html> might be helpful, too :)

Please also note that Generics aren't "Templates in C#/Java" or vice versa... they follow a different concept.