When people are looking for reliable information, they don't trust and use search engines quite as much as you think. According to USC's Center for the Digital Future, only 51% of people currently believe that “most or all of the information produced by search engines is reliable and accurate.”
So does everyone settle for the engines anyway? No, it's only part of the mix. Recently the British Library asked people about the specific ways they searched for reliable articles. Regardless of age, personal recommendations were always cited as an important source -- beating out Google Scholar every time.
Younger students between 17-21 relied on recommendations, journal publisher sites and electronic tables of content, along with Google Scholar somewhat less frequently. Libraries were used more by the time researchers reached age 22, and spiked for the Baby Boomers. So there's clearly a mix of discovery tools used in the research process today.
This British study claimed that social networks were still experimental and not a meaningful factor in research. With the sheer volume of participants on Facebook and social functionality on publisher sites, I think there's more activity than is acknowledged here.
Through social networks, it's natural for students to discuss their assignments and everyone to share their interests -- and they will receive informal help from their friends or online groups. It's definitely a more organic and informal approach to recommendations, but draws on the advice of others either explicitly or implicitly.
With the success of Wikipedia, social sharing is gaining additional acceptance among researchers and librarians. Even the U.S. Library of Congress proudly announced their Flickr Pilot Project, which makes several thousand archived images available on the photo site. The Library hopes that Flickr users will tag and annotate the images, so that others can search and learn more about these national treasures.
Based on this evidence, let's abandon the notion that people only use Google or other engines, click on results, and then finish their research quickly. When there's serious exploration and study underway, people use many sources and touch points. They care if their sources are worthwhile and credible, and also depend on others to let them know.