1) There are so many resources. Your best bet is to find 10 or so that teach modern c++ (c++11 & c++14), and follow through with your favourite.
2) Memory management is the biggest difference from Java and C#. Try not to use pointers unless you have to, when you do try to anchor the pointers in stack data (created without new), if you have to use new try to wrap the pointers in RAII classes (smart pointers).
3) C++ is multiparadigm, don't feel required to stick religiously to OOP practices. functional and procedural techniques can be better if you know what you're doing.
4) The stl isn't as... robust as the standard libraries of other languages. You WILL need to search for third party libaries.
The STL is not that bad, cppreference (http://en.cppreference.com/w/) can be really helpful. Otherwise you can take a look at Boost (http://www.boost.org) if the STL is not enough for what you want to do.
And for the language itself, cprogramming (http://www.cprogramming.com) is a really good aid for the latest concepts like auto and decltype
I love the stl, it's almost always the best thing to use in C++ (wrt Cost/Benefit, love me some vectors). My comment was geared to someone who does "Java, C#, Ruby, Python, [and] JavaScript" programming. The most notable omissions in the c++ stl is GUI stuff, which comes standard in C# and Java.
As an aside, TDD and refactoring also aren't as mature in C++ (vs Java, C# and Javascript).
2) Memory management is the biggest difference from Java and C#. Try not to use pointers unless you have to, when you do try to anchor the pointers in stack data (created without new), if you have to use new try to wrap the pointers in RAII classes (smart pointers).
3) C++ is multiparadigm, don't feel required to stick religiously to OOP practices. functional and procedural techniques can be better if you know what you're doing.
4) The stl isn't as... robust as the standard libraries of other languages. You WILL need to search for third party libaries.