Well, I was using C++ for years, but just lately start looking for "all" of its features and how to use them. Knowing every possible thing about C++ is not my goal, even I think it's not possible in some senses. But still, I'd like to know well how to express what I think and understand the effect of others code. I must admit, there was much to learn from these books:
1. C++ Complete Reference (Herbert Schildt),
2. Professional C++ (Nicholas A. Solter, Scott J. Kleper)
3. The C++ Programming Language (Bjarne Stroustrup)
Currently I try to finish up things (for example, answer my own question list), which are directly about C++ itself and then begin with STL.
Given I understand (a subjective statement, but quite well) what's in those books (exclude STL), would it be practical to start reading (now or later, but before completion of C++0x) another book or standard itself? Or that would give too little? It feels like there is always some little bit to discover about C++, so were should one stop? Anyone thinks himself exhausted every language feature? :)
What books would you recommend to others for learning C++ and STL? And something to who are looking for ideas and best practices of actually using language (is, not so much blending with teaching C++)?
Three books is a great start, believe me it's more then most people who post questions on here ever do. I suggest you put your brain to the test and write something, it doesn't matter what it is. If you get from the start to the end of that without any trouble write something more complex until you get stuck, then you know where to look for your next book\tutorial. If you can't think of anything to write then go on the beginner forums here and help some people; fight with me and other contributors over methodology of coding and other non-consequecial crap. Look at your OS and learn the API or try to write a silent cartoon.
These are all just suggestions, I have no idea what your end goal is but I hope these give you some direction. I remember wanting to do a million and one things as I was learning C++ but by the time I got the level where I could, my ideas all of asudden seemed to simple or not worth the effort.
EDIT: I know you were asking for books, but learning happens in practice a lot faster then by reading more then you already have. Forums are a great place to see real world scenarios that might never be in books and are not covered in their tutorials or end of chapter practices. Even if you don't know enough to contribute look at the OP's problem and try to solve scenario out yourself with what you know.
The standard library (and STL by extension) is an integral and basic part of "real" C++ programming. If you aren't using or understanding it yet, I'll allow myself to doubt whether you really got what the books (particularly the third) were trying to tell you.
If you have caught up on these basics, I'll agree that you should read Effective C++ and perhaps Modern C++ design if you're feeling adventurous. Don't overdo it on the books as there is only so much you can learn from them - real experience comes by using the language. With all or most of its features, mind you.