Buying mandatory course books is one of the more expensive aspects of a college education. It's also a cost many students overlook and fail to budget for until it's too late.

But you don't have to buy brand new physical books every semester. You can buy books from a student who's already completed their studies, borrow them from a library, or if you're lucky, download them (legally) for free online.

And one of the best resources for free college ebooks is Bookboon.

Bookboon offers more than 1,000 free ebooks and college textbooks. They are only free thanks to in-book ads. The ads take up no more than 15 percent of the book's total length. For ease of navigation, the books are split into ten broad sections on the homepage:

  1. Accounting
  2. Career Advice
  3. Economics and Finance
  4. Engineering
  5. IT and Programming
  6. Languages
  7. Marketing and Law
  8. Natural Sciences
  9. Science and Mathematics
  10. Strategy and Management

Each of the sections in further sub-divided into more refined categories.

There's also a Premium section. They are books focused on business rather than college. A 30-day free trial is available. Thereafter, it costs $3.99 per month.

How to Download College Ebooks

Using the menu on the left-hand side of the page or the search box at the top of the page, find the book you want to download.

You just need to fill in your details and hit Download. You will have a PDF copy of the publication on your desktop in a matter of seconds.

Each book also has lots of user reviews and a star rating out of five. Check these ratings before you click the Download button. It could save you a lot of wasted time.

How do you find free ebooks for your college course? Do you about a great site you can share with you fellow students? Leave your tips in the comments section below!