The bad news is that released versions of the C++ standard aren't (at least legally) available for free. The good news is that as reference books go, the C++ Standard is rather on the inexpensive side -- $30 US at the present time.
If you want to find out about the next standard, the current draft is N2960, a free download.
Edit: It's worth noting that while the standard was updated in 2003, the changes in that case were mostly pretty minimal. Virtually none really changed the real definition of the language itself. Probably the single largest technical change was to require that std::vector use contiguous storage. This wasn't originally required, but every known implementation did it anyway, so it just turned how things were anyway into a requirement. Unless your question is really arcane, chances are pretty good that the standard you have is entirely adequate.