Spark Notes (sparknotes.com) has a collection of study guides and notes on physics topics from high school to college level classes. Each topic has a textbook and explanation of the theory, including historical reference and sample problems. Each sample problem has a link that breaks down the answer with equations and a written explanation. The information in each section is concludes with an example of how to cite the reference in three different writing styles.
Physics Help Info (physics-help.info) is dedicated to physics tutoring at the high school and college level. The website is operated by a professor of physics with more than 20 years of teaching experience. The professor offers individual tutoring to students and homework help for a fee. There is also a free reference guide that includes basic physics formulas and theories.
The Cramster (cramster.com) homework help website has answers to thousands of questions in more than 50 physics and science textbooks. The textbooks include high school and college level material provided by experts in the field. Cramster also has a glossary of terms and formulas with definitions and examples. The site has an additional homework help feature where you can have your specific homework question answered by an expert. For a monthly fee students have access to the materials and areas of the website. However, there is also a free registration that gives access to some textbook answers and the online homework help forum.
Physics 24/7 (physics247.com) includes a review of physics concepts and theories and a glossary of terms and formulas. The homework help section has sample problems with a detailed explanation of how to arrive at the answer. Each topic also has a quiz that is automatically graded so that students can check their progress.The site provides a directory of tutors for those who want one-on-one assistance.