A thesis statement usually appears near the end of the introductory paragraph of a paper, and it offers a concise summary of the main point or claim of the essay, research paper, etc. A thesis statement is usually one sentence that appears at the end of the first paragraph, though it may occur as more than one. The thesis statement is developed, supported, and explained in the course of the paper by means of examples and evidence.
The thesis statement will reflect the kind of paper you are writing. There are three kinds of papers: analytical, expository, and argumentative. The thesis will take a different form for each of these kinds of papers. 
"If it weren't for the dictionary, we wouldn't know the meaning of words."
"Humans perceive dogs to be cute because of deep genetic coding that stretches back through tens of thousands of years of natural selection for cohabitation with other species"
"In this age of digital media, a record company is an obsolete organization that can be replaced by technology and websites, allowing bands to reach their audience directly."
Jonathan Culler and Kevin Lamb. Just being difficult? : academic writing in the public arena Stanford, Calif. : Stanford University Press, 2003. ISBN 0-8047-4709-1
William Germano. Getting It Published, 2nd Edition: A Guide for Scholars and Anyone Else Serious About Serious Books. ISBN 978-0-226-28853-6. Read a chapter.
Wellington, J. J. Getting published : a guide for lecturers and researcherLondon ; New York : RoutledgeFalmer, 2003. ISBN 0-415-29847-4
John A. Goldsmith et al. "Teaching and Research" in The Chicago Guide to Your Academic Career. ISBN 0-226-30151-6.
Cary Nelson and Stephen Watt. "Scholarly Books" and "Peer Review" in Academic Keywords: A Devil's Dictionary for Higher Education. ISBN 0-415-92203-8.
Martin Horton-Eddison. "First Class Essays" Hull, United Kingdom : Purple Peacock Press, 2012
Carol Tenopir and Donald King. "Towards Electronic Journals: Realities for Librarians and Publishers. SLA, 2000. ISBN 0-87111-507-7.