Coursework leading up to the thesis provides the best opportunity to explore topics of interest. Discussion with fellow students and with faculty advisors is also useful. Graduate students can often build a file of articles that might lead to a thesis topic while writing other papers. [Please note links to databases require your SacLink login if you are off campus.]
How do I know when I've finished? A true scholar is never done reading and researching in his or her field. The simple answer is that this question is decided between a graduate student and the thesis advisor. Once all the things suggested above have been accomplished, the components of Chapter Two will be ready.