The HP Prime is a daunting prospect for those that left maths many years ago but still want to refresh it, or for youngsters that have one for class, but are completely frightened by its apparent complexity. I feel it myself: my math knowledge is too small and too old for most of the things that can be done with it.
Well, there is a French site that has created an abosolute beginners' guide to the HP Prime. You can find it here, in its English translation, courtesy of Moravia, an HP distributor in Europe.
I copy also the link to the French original. Not only for the French among our readers - it is another proof that oftentimes, the original reads better than the copy. The beauty of the French language helps, too (and I am not French!)
I find especially interesting the programming part. Even though it is thought for French secondary school, it is thought-provoking and it gives you many hints to develop your programming skills with the HP Prime