That depends on a number of factors, such as how much experience you have with programming in other languages, and whether you are primarily interested in creating graphical applications.
The biggest change between VC++ 6 and VC++ 2002 (and above) was the introduction of the ability to create managed (.Net CLR) applications. If you intend to utilise this feature then you may be better off with a more recent guide. If, however, you are primarily interested in creating console or non-.Net applications, or just want to learn C++, then a VC++ 6 book would be a perfectly good starting manual.