Good resources for learning

[Lorenzo Bertini]

Dear list,

Forgive me if this is the wrong place to post. Reroute me to the right 
place if needed.

I am a computational physics student working on a small library for 
Monte Carlo simulations of spin systems. Having been a GSL user for 
quite some time I decided to "imitate" the practices I've seen in this 
library: allocating good data structures, having templates for 
boilerplate code, etc.

I keep getting stuck. One time I have a struct with thirty members, the 
other I'm passing twenty arguments into a function, and so on. I'm used 
to the C language and I can understand most of the GSL codebase, but I 
lack direction on this project.

What could be some good resources for learning to write C code like I 
see in the GSL? Right now I'm reading "C Interfaces and Implementations" 
from D.R. Hanson.

Thanks in advance, and all the best
--
lorenzo