We all have different ways of recording information etc.:
Research logs can be simply keeping a notebook with any kind of comments you have about anything related to your project. The log can also be more structured. For example, you may have sections on:
It is a valuable part of your project. In it you document insights as you have them (you may not remember them later). These can be daily entries, or comments you enter whenever you do anything on your project. A good idea is to date when you write something down.
Examples of the "Matrix Method" one widely recognized and used approach for managing your literature search activities, are described on this page
Some Tips on Recording the Information Found, on Taking Notes etc.: