I need to read more code... but when I do get the time to read code I never start with "main" I start by searching for a feature I am interested in and then bra

I need to read more code... but when I do get the time to read code I never start with "main" I start by searching for a feature I am interested in and then branching out to see how this feature fits in with the whole. I normally use N++ and open a huge number of files at once, its important to me to be able to switch between files quickly and I don't want the bloat of an IDE.