GrabMyBooks for Chrome
You will need to have at least java 6 installed because a small piece of software called GrabMyBooks Tools is needed for the extension to work.
So download the GrabMyBooks extension from the chrome store.
Then once installed, there is a new menu with an ereader icon.
Click on the first item of the menu My Book.
It will display a page allowing you to get the GrabMyBooks Tools java program.
This program has to be running for GrabMyBooks to be able to work.
GrabMyBooks is then ready to create multiple ebooks!