There is a website written in German called Gramadach na Gaeilge that has good explanations of most of the everyday grammar that you will encounter. There is an English language translation of that German website available here.
I thought that you had to add the "h" when there was an "an" in front of it, like "An fhear agus an bhuachaill".
Am I completely wrong, or is there something I'm misunderstanding?
In fact, is there a place that explains that 'h' in greater detail?