If searching for physics textbooks online there are many outlets from which to choose, from specialist academic book websites to the major online retailers. Shopping around and doing a bit of research beforehand will safe a significant amount of money in the long run, especially if you need to buy several books.
Physics textbooks cover matter and subsequent derivations and how the universe works. The subject has been around since the sixteenth century, although research today tends to cover astrophysics, quantum mechanics and cosmological phenomena. The books take you through some of this more recent research after it has taught you the basics. Usually when buying for a course you are about to take you will be given a list of books that you need to buy. This is because each book will cover a separate branch of physics and go into more depth on each; they will also normally include exercises at the end of each chapter to test your learning so you can see if you have grasped the core concepts. As these books are revised and updated every few years with new areas, new discoveries and additional research, it is important to ensure you buy the latest edition; a quick search on the internet will let you know when the publication date of the most recent edition.
In the last 2-3 years the eBook has gained a foothold in this market. There are now several eBook readers on the market that allow you to purchase your books online download them to the reader which you can then use in class. The files are now easier to find as they are sold through several online retailers. If you need some physics textbooks, give this some consideration as there can be a lot of money to be saved.
For those who prefer the physical book you can save money by buying used physics textbooks online, this allows you to buy a book second hand. The sites you buy them from will provide a description as to the condition of the book. If you do not mind your books in a less than perfect condition, this will also save you many pounds.