The absolute essentials for learning conversational Russian fast, in my opinion are:
Get an audiocourse to help you get used to pronunciation and grammar (I prefer Michel Thomas but others prefer Pimsleur
Get a Russian frequency dictionary. This one has stress marks, romanization and Russian to English example sentences. Since the most common 2000 words make up like 90% of all vocabulary you'll use on a daily basis, I think these are really crucial.
My absolute essentials for learning conversational Russian fast: