These are materials that can help with C.
The USENET comp.lang.c group does not let a question go unanswered. The comp.lang.c FAQ page is very helpful, and can be purchased as a book.
LCLint is a superior version of lint
for checking C programs, and integrates with the MS Developer Studio
The actual translation had to be done in an automatic manner to prevent the introduction of new bugs. In the end I used the forc package.
f2c is free, openly available from many sites, and often installed on Unix systems. The Fortran compiler in a Linux environment is often f2c followed by the C compiler. The intermediate C output can be saved, and seems to always work as the Fortran was intended. The code is a train wreck not meant to be read by a human. For instance, multi-dimensional arrays are converted to 1D arrays.
forc by Cobalt Blue is the translation program I used to convert Cloudy. They are a bit pricey, but all the code needed to support the translation is provided, and you end up with a stand-alone program that looks like it might have been written by a person.
These are the books I found most helpful in learning C. The notes here are based on them. They appear in the order I would recommend reading them,
Practical C Programming, Steve Oualline, O'Reilly & Associates, Inc., 1997. This book is fun to read, and very practical. I read Osterbrock's book three times while learning nebulae. I read this book three times while learning C.
Expert C Programming: Deep C Secrets, Peter van der Linden, SunSoft Press, 1994. This book and the following one were written by people who write C compilers. They have seen all the mistakes.
C, A Reference Manual, Samuel P. Harbison and Guy L. Steele, Printice Hall, 1991