Other than that there are many sites (free) and Many learning sites (paid) And many many books but it will depend on what you want to learn. If General linux I would recommend a book titled Running LinuxHome | Linux Journey
linuxjourney.com
or here:Running Linux, 5th Edition
You may be contemplating your first Linux installation. Or you may have been using Linux for years and need to know more about adding a network printer or setting up … - Selection from Running Linux, 5th Edition [Book]www.oreilly.com
or hereThe first place to start:
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