A thesis statement is the main idea of your research paper. It is the point around which your entire argument will support/prove/return to. Here are some hints and tips for writing a thesis statement (and sticking to it!):
Paraphrasing or summarizing a source quotations can be a good alternative to overusing direct quotations in a research assignment. It is also a useful skill when synthesizing information to demonstrate understanding of the material. Paraphrasing or summarizing a source means to explain the idea of the source quote without using the exact language of the source or to explain it in simpler terms.
Paraphrased or summarized sources still need to be cited.
Direct quotations of sources should be used sparingly, especially long, block quotations and only when they contribute to the scholarly aspect of your research paper in a greater way than summarizing the source can. Directly quoting a source means to use the exact language of a source.
When using a short direct quote, less than four lines of text, the quote can be incorporated into the paragraph, bracketed by quotation marks followed by the in-text citation appropriate to the source.
For direct quotes longer than four lines of text the quote should be separated from the prior paragraph in the form of a block of text, formatted according to the citation style your instructor prefers and followed by the correct in-text citation.
Always, always, always attribute credit to the original author of a source used. Avoid plagiarism!