Conducting research on philosophical topics and figures can be overwhelming. Where do you begin? The following resources are a few relatively quick ways of becoming familiar with the available body of research.
Handbooks or compendiums on the figure, school, or topic you are researching will often contain essays by scholars in the area on major areas of research and debate. The editor's introduction may also be especially useful, as these generally serve to contextualize the essays in the volume relative both to each other and to broader philosophical discourses.
Handbook series of note include:
Although there may not be a book specific to exactly the topic you're looking for published within the last few years, familiarizing yourself with what is being put out as scholarly work by major academic publishers is a good way to (1) see what topics are being worked on by scholars in the field and (2) what other, older works are being cited by these scholars.
Examples of major academic publishers include:
Note that it may also be helpful to consult specific publishers for particular areas, e.g. presses that specialize in Continental Philosophy include:
A number of encylopedia-type articles aim to summarize main points of a topic, figure, idea, etc. while suggesting possible avenues for further research.
Three peer-reviewed sources online include:
Depending on your area/approach, you may also want to consult more specialized volumes, such as the following:
Although they can quickly become outdated, bibliographies--especially annotated bibliographies--provide the researcher with a curated list of books, articles, and other resources that enable focused, informed research. One good online example:
Two disadvantages of bibliographies worth keeping in mind are that they can suffer (more or less) from biases in selection by the author of the article, and they tend to focus on "major issues" and "major works," thus omitting less well-known works that may nevertheless be more relevant to your research.