100 words a day is a very ambitious target, but by no means impossible. For my French and Spanish A-levels I revised a lot of topic-specific vocab at this pace, albeit only over the period of a couple of weeks, and I had no classes, work, etc and so could, as someone above put it, "live and breathe" the target language. And remember this was revision, not learning from scratch.
I'd recommend learning vocab grouped by subject matter, eg. food, music, sport, whatever, as this can provide a good basis for the learning when you at least know the vague ballpark the word is in. After working on one subject area, over the next couple of days, read articles or websites about that subject in order to cement the knowledge. I've found vocab learning is a matter of repeated and prolonged use, not cramming. And as mentioned previously, the importance of listening and immersion cannot be over-estimated!
Although it doesn't support Mandarin, I can strongly recommend the free Interlex (
Free Vocabulary Builder) software for learning vocab in a variety of languages for anyone else reading this. It allows you to test yourself with custom word and phrase lists.
Good luck JeremyW (let us know how you get on!), plus any other linguists out there.