This book is the ultimate if you are serious about creating truely strategic marketing plans for your business. It basically gives you all the fundamentals required and takes it so much further, any company big or small can benefit from the knowledge in this book. It has been updated well and questions some of the traditional theories, i.e. features an updated SWOT.
Also, if you read the intro it gives you a bit of a guide on how best to use it, so if you just need to get a breif overview of how to structure a plan you can pick the best chapter/s to read, if you want to go more in depth you can dip in and out of it.
All in all, this is an essential text for marketers, don't bother with Kottler he hasn't done anything good in 15 years.