Reference books such as encyclopedias, dictionaries, handbooks and biographies help you find factual and background information about your topic.
It is advisable to look at more than one source of information to get the most information and to have a more balanced view of the topic.
Google and Wikipedia could be good places to start your search for general and initial ideas about your topic. But you will always have to use Library resources to get more credible information.
Henderson's Dictionary of Biology by 
Oxford Dictionary of Biochemistry and Molecular Biology by 