Depending on your subject, web resources like Google, Google Scholar and Wikipedia can be a good place to START your research, just don't finish there. The following tips can help make your web use more efficient:
Where do you get your Information?

A lot of useful information is not freely available on the web. It is proprietary, meaning someone--an author, a publisher, or institution--owns the information.
You need to critically analyze and evaluate the information you intend to use.
There are still books in the Library. And other print and analog resources that do not exist on the Web.