Hmmm... rather inadequate as far as depth is concerned. Really, I can get more in-depth material off the internet just by Googling.
Sadly it's very short. It spans quite a few subjects, for instance a short bio, and some background and a short treatment of most of her works, but each of them not treated in much depth.
On the other hand, it certainly deserves at least 3 stars because it is quite adequate in scope, if not in depth.
So, if you don't know a thing about Virginia Woolf, this is indeed a good place to start, as the word "introduction" implies. However, if you have studied Virginia and her works a bit already, rather look for something more substantial.