It's sometimes easy to forget this, but Google is not the only search engine on the internet! If you are going to use the Web for research, then it's good practice to make use of other search tools to ensure that you do not miss information that could be relevant to you. If you enter the same search into 3 different search engines, you will almost certainly get 3 very separate sets of results.
You can see how this works in practice by looking at the Thumbshots site; this allows you to compare an enquiry between two different search engines, and gives you a visual representation of how the results differ. You might also like to take a look at Jux2, which compares results from 3 of the biggest search engines, and shows which sites each of the engines fails to find. Or how about using Trovando as the starting point for all of your future Web research? This will allow you to quickly use a wide range of search engines from a single search box. Google may seem to give you the information that you need quickly, but sometimes a look at other search tools will reveal material that will be invaluable to you.