Linux Server Management Books/Tutorials Recommendation [Web Hosting]

I own a web hosting company where we have our client's websites hosted . We have a linux server with cloud linux . Being into web hosting business there are other packages also installed and running like WHM , WHMCS , cPanel etc .

The issue is our server administrator/manager is no more going to be with us due to his real life issues .

I myself is a PHP/Mysql Web Developer and a Windows user . From our team , i have to take the initiative to learn everything from start i.e starting from linux to linux web hosting server management. I searched google to find a dedicated article on this problem or process . I am looking for some tutorials/books recommendations in a series which may help to achieve my goal . I would appreciate all the help i get .