The how to digital dj fast course is excellent if you are still lacking in some basics.
So it goes into:
How to get the right tunes, basic mixing, basic beatmatching, the 3 or 4 most basic transitions, gear setup, which gear to use, how to use the headphones correctly etc.
So it is aimed towards total beginners or people who already got into DJing a bit, but did not learn their basics fully. Especially for the second audience some parts may be redundant or already known, it can however be a good thing to hear this basics again from a professional and to really get them down.
I always consider the basics very important, as when you can do all the basic mixing and stuff in your sleep, it is way more easy to experiment and develop your style and even disregard some of the basics from time to time, as you KNOW when you are doing it…