Quote from optioncoach:
Rosetta Stone is not good in my opinion. It just tries to get you to mimic the language for learning, but does not try and get you to truly learn it well. True speaking is hard to get from a book since you nned to interact with a speaker or teacher. However there are good books which go over conversational aspects that build a good foundation.
I have studied Spanish and Japanese so have some detailed experience in languages. Is there a specific language you are interested in, maybe I can suggest some books depending on whether you are total newbie or have some basic background but looking for more conversation.