One little point of trivia for ShakeyX. Historically, at least, pronouncing the unstressed О with its full value (as о, not а or ə) was an important marker of "regional dialect" -- kind of like pronouncing or not pronouncing the "R" after a vowel in American English. (Some people "paRk the caR"; others "pahk the cah".)

Nowadays, хəрашО (based on the Moscow dialect) is the "standard educated pronunciation", while saying it as хорошО sounds sort of "redneck-ish", as far as I understand. However, this non-Moscow pronunciation has gradually become rarer because of radio, TV, and other mass-communication forms.