Knowing C is a prerequisite for learning C++, right?

Wrong. The common subset of C and C++ is easier to learn than C. There will be less type errors to catch manually (the C++ type system is stricter and more expressive), fewer tricks to learn (C++ allows you to express more things without circumlocution), and better libraries available. The best initial subset of C++ to learn is not "all of C". See Learning Standard C++ as a New Language for a discussion of the choice of C++ constructs, techniques, and libraries for early learning. For an example of books that takes that approach systematically, see Stroustrup: Programming: Principles and Practice using C++ and Koenig&Moo: "Accelerated C++" from Addison Wesley's C++ In Depth series.  more