This Web page is great if you’re struggling to get started on your thesis. It not only provides a definition of thesis but also provides some questions to ask yourself as you’re writing it.
This Web page does a nice job of showing how thesis and claim are similar and of providing strong examples of both thesis statements that need revision as well as the revised, workable thesis statements/claims. It also talks about the different types of claims you might use in your paper and when it’s most appropriate to use certain types of claims.
This Web page has a good step-by-step to writing a good thesis statement and how to evaluate your own thesis statement, as to whether it’s strong enough. There are examples at each step of the way.