i had to put together something resembling a compiler for a class, i used mainly two sources:

for the theory part: http://www.diku.dk/hjemmesider/ansatte/torbenm/Basics/ (Basics of Compiler Design - Free book)

actualy put something together: http://www.dabeaz.com/ply/ (PLY (Python Lex-Yacc))

maybe not the solution for real world use, but helped me jump past some nitpicking parts with the C / lex / yacc implementation.