Billy for Kids:

A website for beginners and youth. It has animations and is it fun to navigate. It comes in over 11 languages. It has a simulator of a spaceship to travel through the Solar System and planets in other star systems.
billyforkids.info

Future of Mankind:

Website in English. It has a lot of information about Bily Meier, including a photo library and several of the contact notes.
futureofmankind.co.uk/Billy_Meier/Main_Page

Michael Horn's Website:

He is the representative of the Billy Meier case in the USA. His site contains plenty of downloadable material, including prophecies and predictions, photos, videos, and a blog. Michael has produced several documentaries about the Billy Meier case.
theyfly.com