Handbooks and encyclopedias provide overviews of topics. The entries will describe the key themes, readings, and authors and are a good introduction to a topic. They should have short lists for further reading which can guide you to key or critical sources on a topic. This is especially helpful when a topic is new to you - it's easy to get overwhelmed by search results when you are new to a topic.
Some examples of online handbooks and encyclopedias relevant to morphology: