"Min" goes with masculine nouns - that takes the article "en": en bil - bilen min
"Mitt" goes with neuter nouns - that take the article "et": et hus - huset mitt
"Mi" goes with feminine nouns - that take the article "ei": ei bok - boka mi
"Mine" goes with plurals.
That only means "my book" (and is in feminine gender, incidentally. Norwegian is moving toward having neuter and common, ie masculine, genders, but feminine is still correct. Some dialects prefer using all 3 genders.).