Getting Started:

First, make sure you have Kindle for PC (link below) installed on your computer.

Kindle for PC lets you easily read eBooks downloaded from the Kindle Store, but it doesn’t have any way to add other eBooks directly from the program.

To add eBooks, you can sometimes download and double-click on the books, and they will open in Kindle for PC and be automatically added to the library.  However, this does not always seem to work.

So instead, browse to your Documents folder (simply click on the Documents link on your Start menu), and double-click on the My Kindle Content folder.

This folder contains all the Kindle books you have downloaded.  If you have other eBooks you would like to add to Kindle for PC, simply drag-and-drop or copy and paste them into this folder.  Here we have a .mobi formatted book downloaded from the Gutenberg Project that we’re dragging into the folder.

Now, close and reopen Kindle for PC.  It should now show your new eBook right beside the eBooks you have downloaded from the Kindle Store.

These eBooks work just the same as the ones downloaded from the Kindle store, and you can change font size and add bookmarks just as with other eBooks.

Conclusion

This is a great way to read eBooks from across the internet on Kindle for PC.  Wikipedia’s Kindle page has a list of websites that offer eBooks formatted for the Kindle, so be sure to check it out for more books.

Links

Download Kindle for PC

List of websites that offer eBooks that will work on Kindle – via Wikipedia