I learned C from “C Primer Plus” about a decade ago and I thought it was terrific:

C Primer Plus (6th Edition) (Developer's Library) https://www.amazon.com/dp/0321928423/ref=cm_sw_r_cp_api_i_bg...

What's the rush?

http://norvig.com/21-days.html

Learning C is difficult because you need to know how the machine actually works. Trust me, there are no shortcuts. The year can be 2036, learning C will be the same.

With that said, these books are excellent:

http://www.amazon.com/Programming-Language-Brian-W-Kernighan...

http://www.amazon.com/Expert-Programming-Peter-van-Linden/dp...

http://www.amazon.com/Primer-Plus-6th-Developers-Library/dp/...