Ruby is waay more than just a "slightly different syntax and grammar", and you can't really understand what's happening behind the scenes in rails until you understand the tools at work.

If you've got the basics of Ruby down, get this book and take it to the next level

http://www.amazon.com/Metaprogramming-Ruby-Program-Like-Pros...

As for the gems in rails..study their code, learn what they try to do, then program it yourself, else you might spend forever fighting with poorly documented and fragile gems, that were never really intended for long term production use anyway..

just my 2 cents..