Researchers, psychologists, and scientists in the field publish the conclusions and findings they make in their studies or research in academic or "scholarly" journals. These sources - which we typically read online in library databases - are often peer-reviewed, which means that other scholars and scientists in the psychology discipline agree that articles are methodologically correct and the findings are interesting or important before publishing them. This is significant because it is a filter that ensures that journal articles are held to the highest standard for reliability and authority.
The science life cycle of information, below, summarizes this process of creating academically-valid information. Click the picture for a tutorial that describes this cycle in greater detail. Note: The "Find" component is specifically about another library. (Source: University of California, Irvine Libraries)
Most Psychology books that you can take out of the library are located in the call number
However, since psychology is a very broad subject, you may also find information in these call numbers:
HM-1001 to 1281--Social Psychology
HQ-2035 to 2039--Life Skills
LB-1050.9 to 1139--Educational Psychology
RC-321 to 571--Neurology and Psychiatry