The library can be a confusing place. Your questions are likely to fall into multiple subject areas. As you dig around, pay attention to key words used in the titles of articles or books. Keep a running list of key terms and try breaking your question into parts. For example:
Key words to start with might be Facebook, social media, globalization, information technology. As I dig further, I will probably narrow my focus and add different terms: privacy, protest, surveillance if I become interested in how Facebook influences social movements. Or I may decide to focus on what Facebook use does to the environment so use environmental impact or electronic waste. As you search, keep in mind what you are looking for and what seems most interesting to you.
Remember: your focus should be on how academics have studied these issues, not on newspaper articles or opinion pieces - though those may give you ideas. Here are some hints:
As you search a database, see if you can limit to "peer reviewed articles."
Looking at potential sources, see who the author is (a scholar? a journalist? a celebrity with opinions?) and whether they explain how they arrived at their conclusions (methodology). Having citations to other sources is also a sign that a book or article has an academic audience in mind.
There are at least three modes of search practiced by historians.
Strategic Serendipity - putting yourself in a place where something interesting may turn up.
Deliberate Inquiry - searching databases, refining search terms and parameters as you go
Tracing conversations - using footnotes to trace ideas both forward and backward in time.
You're likely to use all three of these modes throughout your research. Think of it as a cycle - at first you may not be sure what you're looking for, but as you dig and explore, you learn more and your question gets sharpened, more focused. You may find out things are far more complicated than you realized or you may find a primary source that throws up new questions. It may feel like you're going in circles, but that's how research works.