I suggest writing a blog in English. Practice is probably the best way to learn. There is also http://english.stackexchange.com if you have specific questions.
> Program well in c in userspare (Currently reading 'The Linux Programming Interface')
In my experience, reading other people's code is the best way to get better at a language. I don't have much experience with C but I guess there are a few projects that would be interesting to read here: https://github.com/search?o=desc&q=language%3A%22c%22&ref=si...
Relevant links: http://stackoverflow.com/questions/925754/resources-for-lear..., http://www.amazon.com/Beautiful-Code-Leading-Programmers-Pra...
> Embedded development (I don't even know where to start that one...)
I am currently learning embedded development (maybe we could help each other?).
I would love to!
And thanks for the links, I will try/read them.