Hello and welcome Mr. Admin! And i hope u have great time here.
First of all i want to say something about linux i think its great for u to know because all of hackers needs it, so you'll have no problem with that. Also because of that linux becground and othe experiences which you've said you dont need to learn network basics too.
But another thing which i always recommend is virtualization i dont know if u know it or not but u will need to work with atleast virtual box however if u learn the concepts and vmware it will be better.
The next thing which i want to recommend u to learn is programming which is extremely required for exploitation. I suggest u to learn assembly and python and html (its so easy!).
About OSCP im planning to get it next year and all i know about it is so hard and much better than CEH.! You can find good info about it in offsec's website.
And i think one of great books to learn pentest is this:
www.amazon.com/gp/aw/d/1597494259/ref=redir_mdp_mobileHowever u can find many books with a simple google search.
Good luck