Get a frequency dictionary asap. By far the best investment if you want to broaden your (actually useful) French vocabulary quickly. in day to day speech, the most used 2500 words make up like 90% of all spoken language. This book also provides you with IPA phonetic transcription and French to English example sentences. It's kind of like a bilingual book if you look at it that way.
Have you looked into a French frequency dictionary yet? Sounds like something you might find handy. I love them and have used them successfully for Spanish, Italian and French... And consider them a bare necessity (usually in conjunction with a Michel Thomas audio course.
Anyway, back to the French Frequency Dictionaries: