The Free Dictionary reads that "good" is normally an adjective, which means that it is used to modify nouns. It also reads that "good" may be an adverb only in informal speech. In this case it is used to modify verbs. Being an intermediate English language student, I feel that first of all I would like to learn the proper meanings of words. Indeed, it’s always useful to know all nuances.

good - definition of good by the Free Online Dictionary, Thesaurus and Encyclopedia.

good vs well - Common Mistakes and Confusing Words in English - Learn English Mistakes