This database looks a lot like Academic Search Premier, but all of the publications are from psychology journals and books. PsycInfo has powerful search features that let you narrow down your results to just the articles you want.
Although the search options aren't as powerful as PsycInfo, Google has the best natural language search technology in the world. If you're having trouble finding material on your topic, and especially if you aren't sure what keywords to use, Google Scholar is a great place to start. It's also great for casting a broader net - if you've found one or two good publications, you can locate related publications.
These online encyclopedias are a good place to delve into your topic and get new ideas. They often also include references to research publications. You shouldn't cite encyclopedias in your academic papers, though! They're best used at the start of the research process.
Confused about what constitutes empirical research? Can't tell quantitative from qualitative? Or have you run into a new method, and you want more information? These books should provide the overview you need. As with other encyclopedias, don't cite these as sources in your research papers.