The Puerto Varas (Chilean Government) Tourism Office is easy to find – in person. Very difficult using the internet. They are located at San Francisco 431 and the telephone number is: 065-232437. There is also a privately owned office on the pier called Casa de Turista. Their neat little glass hut (pictured) is located across from the central square directly on the lake. They are very helpful and friendly and have a few nice gifts you can buy. They have lots of free brochures and maps as well as information on tours. They have an excellent view of the lake, but I am a little unsure where all the sand near the front came from. Their address is Av Constanera and their telephone number is: 065-237956.
I have listed a website below for the official Tourist Information, but it does not work properly all the time. Good luck figuring out their email!