Understanding programming theories for creating robust code

[Newbie19]

I'm an intern at a software company and I was hired not knowing much about software, I know tons about hardware though. However, for my first major multi-functional program, I need to understand the theories behind programming so that it is reliable.
Where is a good place to look for theories on programming or books for that matter?

Thanks,

[pbmods]

Changed thread title to better describe a problem (threads tend to get more responses when the title contains nouns *and* verbs, with emphasis on plural).