Books are a great source of knowledge and entertainment. With the rise of the internet, downloading books has become more accessible than ever. There are some best platforms to download books for free, textbook solutions and many more e-books.

ManyBooks - ManyBooks is a website that provides access to thousands of free eBooks. You can download books in a variety of formats, including ePub, Kindle, and PDF.

Open Library - This website is a digital library that allows you to download over 1.7 million books for free. You can also borrow e-books for a limited time if they are not available for download.

BookFHR - This website is a great resource for free engineering books. They have a large collection of books available for free download.

Libgen - This is a popular website for downloading academic books, including engineering and math textbook solutions. They have a large collection of books available in different formats, including PDF and EPUB.

Crazy for Study - This website is a great resource for free books. They have a vast collection of books such as science, social science, engineering, business, math textbooks, including calculus, algebra, and statistics and many more.

Internet Archive - The Internet Archive is a non-profit organization that provides access to millions of books, movies, and audio files for free. You can find books in a variety of formats, including PDF, EPUB, and DAISY.

Public domain books - Many books are in the public domain, which means they are no longer protected by copyright and can be freely downloaded and distributed. You can find a list of public domain books on websites like Project Gutenberg and the Internet Archive.

Librivox - This is a volunteer-run website that offers free audiobook versions of books in the public domain. They also offer e-book versions of these books, including PDFs.

E-Books Directory - This website offers a wide variety of e-books that are available for free download in a variety of formats, including PDF. They have books in a wide range of subjects, including business, computer science, engineering, and more.

Project Gutenberg - This is one of the oldest and largest sources of free e-books. They have a collection of over 60,000 books that are in the public domain and available for free download in a variety of formats, including PDF.

It's important to note that not all the books on these websites are legal, so be careful when you are downloading and make sure you are not breaking any laws. Also, some of the books might not be available in all the countries, so be aware of that.

Always check the source and make sure it is reliable before downloading any books.