A vital reference for those needing the reliability and detail you don't find on wikipedia, invaluable as a 2nd year undergraduate chemistry text book and highly useful for those needing to check their facts while teaching chemistry, especially at A level and above.
The book itself is well organised, the information within is presented in a clear accessible manner. It is easy to find relevant information on an enormous range of compounds, with useful asides to give contextual information relating to industrial processes, biochemistry, and some newer developments in nanotechnology!