I have attempted to learn a new language before, but personally for me to retain the words I could only learn maybe 10/week. I would go over and over and over them. 100 a day seems a bit much unless that is
all you are doing. But if you want to attempt it, flashcards would certianly come in handy.
Just for another idea, maybe listen to mandarin tapes or programs etc. while doing your 5 words a day (or however many you choose). Hearing the language a lot might be of great assistance.
These are just my own ideas, I'm not a teacher or anything
Good luck.