Has anyone used the Russian English dictionary by M.A. O'Brien? I would like to know if it's a good dictionary to buy before I do so over the internet. Thanks!
I am not familiar with this dictionary but I looked it up on Amazon and it appears to have been first published in the 1930s. I would NOT recommend a dictionary that was this old. Spoken Russian has changed significantly in recent years taking lots of foreign words and russifying them - to park is parkovat', to recommend is recomendovat', business is biznes, lunch is lainch, etc.
There is some information about this sort of thing on my website and I also suggest looking at amazon for reviews.
Ruth

I'd second Everbrite's advice that you need a modern dictionary - not just the Russian, but also the English in older ones can be very dated. Probably the best Russian English dictionary is the Oxford one, although it has its weaknesses. Also it is of course based on British English, which you may find confusing.
There's quite a good American based one by Kenneth Katzner.
By the way, as soon as your Russian is reasonably good, I'd definitely recommend getting Ozhegov's Russian (to Russian) dictionary, as it gives much better information on words' meanings and their uses, and a full breakdown of all the stress changes and irregularities, which even the best translation dictionaries don't seem to.

The Oxford dictionaries are really the best, but there is a decent paperback one that came out a few years ago that's a bit more American-centric than British-centric as the Oxford ones are. I can't check as I'm not at home, but I think the Katzner one #2 talks about is what I have. The Oxford ones are fine though, but there is no way at all I would use a dictionary published in the 1930s, even if it was free.