Select one source you think might be helpful for your research. Evaluate the source, starting by using the information provided by the database or catalog.
Once you've begun selecting sources, you'll need to evaluate which sources will be the most useful for your paper. You will need to consider the authority of the person or group who created the source, as well as the purpose of the source and whether it's relevant to the exact topic of your project. You may also want to consider things like whether you have the background knowledge to understand the source, and whether it's old enough that it might be outdated.
Authority on a subject can be established through credentials like academic degrees or publishing history, but it can also come from experience: in the case of a topic like the religious music of South India, academics who study this music or the surrounding culture may have authority, but so do musicians and other members of the community. If you can't evaluate the author from the source itself, try searching to see what else the author has done.
Relevance should also be considered carefully. Not every source located in your search will be equally relevant to your work. Some may be so broad that there is little information that is directly useful to you, or they may be focused on such a narrow topic that your area of emphasis isn't discussed much. Or, the audience the source was created for may be too different for the source to be useful; for example, a children's book or a tourism marketing video may include input from authoritative sources, but not be very useful or relevant for your needs.
In researching world music, you're evaluation may look a bit different from some other topics you may have worked on. One important thing to consider is whether different types of authority are being represented in your list of sources. You may want to consider whether the perspective of the community that makes the music is being represented as well as the perspective of academics.