This is fine; there are lots of similar "intro to quaternions" pages around.
One thing I haven't seen yet is someone showing how to interpolate between multiple quaternions over time, smoothly. (Hint: it's not slerp.) It's a non-trivial problem.
See "A General Construction Scheme for Unit Quaternion Curves with Simple High Order Derivatives" (Kim, 1995) for a simple extension of Hermite splines to Lie groups, including unit quaternions.
