I already use the Relaxation CD also available from NKT and found it extremely useful in my meditation practice. I also use various guided meditations available on CD and in MP3 format from other sources. Hopefully, this will evidence that I am not a complete beginner and not biased towards NKT products in any way. I'm not part of this Buddhist school of thought as such, but do on occasions attend their classes and my experience has always been very positive. Whatever my background, the stars I awarded to this product are relevant to the quality of the product and my own opinions of it alone, not driven by a hidden agenda. I simply wanted to address this openly and honestly for those to whom such affiliation would be of interest.
The meditations are between 9-15 minutes in length. It's neither good nor bad. It simply depends on how you're going to use them. I use them in the morning, and wouldn't have time for anything longer than that. If you wish to meditate for longer than that, perhaps bear that in mind. I did two in a row before as well when I had more time and that worked well too.
I personally do like the female voice that guides you through the meditation. I find her neutral and unobtrusive. It is however very personal and I can understand that her voice may not be to everybody's taste. All I can say, and it's my review, is that it works for me.
The only slightly negative comment, is that I felt that I would appreciate a little more structure and guidance. Perhaps, there's a method in the way they structured it that I'm not seeing at the moment, but I felt a little unsupported. I may be too used to meditations that focus on breathing that find those that don't more challenging, or less to my liking. I will continue using it though and if I have an epiphany on that point, I'll keep you posted.
I found meditation very helpful, even though not easy to learn. I hope that you enjoy it and find it beneficial too.