The St. Louis de Montfort book is a little too mystical for a beginner and I think it would probably hamper their development. It might even frighten them away. Worse yet, if they are not ready spiritually for the pure gold of St. Louis de Montfort's book - it may completely spiritually ruin them. Sometimes people will gain some knowledge but not have the maturity or the wisdom to undertake such a mystical book.
Sigismund, why not just make your own little pamphlet up - you know the prayers and the mysteries, so you could print it in a format and font that is pleasing to the eye and you could give instructions to whoever it is you are making this for. Even pray the rosary with the recipient of your good work a couple times to help them get the hang of it.
Tell them one thing though and that is that the rosary is a lifelong journey so they should undertake it with patience and sooner than they think they will develop a love for it.
Another tidbit, have them start out by just praying one decade for any intention they desire and, as they grow spiritually, or at least become more aware, then they could be encouraged to do a second decade daily.