What would be the best language if I want to develop a range of Linux related things. I want to make kernel patches, Linux programs, contribute with other projects, etc. Where and with which language do I start?
The best way to decide which language is going to be useful to you is to look at the source for the projects to which you wish to contribute. Take a look around popular code repositories, such as github, google-code and sourceforge.
Diving into a language like python may be useful for some scientific projects, but not at all useful for something low-level like linux-kernel development.
I want to make kernel patches
The Linux kernel source tree is currently:
So start with The C Programming Language and go from there!
Good luck!