I've been reading this blog called The Essential Secrets Of Songwriting by a gentleman called Gary Ewer on a regular basis lately, there's a lot of posts about putting together melody and harmony, also a good read for structural advice and fitting lyrics to a melody.
The circle of fifths is important to know for any kind of modulation. I'd suggest, if I may, that you look for songs you think sound anything like what you would like to play, then figure out which chords are playing.
Minor verse section - Major chorus tend to work very well at times.
Happy writing
