How is the case system compeltely different from Latin? Are there cases other than the typical nom, gen, dat, accus, instr, etc. or are the endings simply diffrerent?
I'll just mention a quick thing or two.
Nouns have (in practical terms) just two cases (nominative-accusative and genetive-date, theoretically there's a vocative but it seems to be used even less than in Polish). And the case is indicated by the article not the noun form itself. For example:
băiat - boy (dictionary form)
un băiat (a boy nominative/accusative)
unui băiat (a boy genetive/dative)
băiatul (the boy, nominative/accusative) - masculine article -ul (the final -l is often dropped in pronunciation)
băiatului (the boy, genetive/dative) - masculine article -ului
Adjectives agree in number and gender but not in case (though sometimes an adjective will the case-bearing article instead of the noun).
There are also free standing articles that can help indicate case too but they're a little hard to explain here.
Here's a wiki link though the writing could be (a lot) clearer.