I think you should purchase a fan relay it will make your install much easier. They come with instructions so you can just connect it and not worry about terminal numbers.
But as far as the terminal numbers go on a relay each terminal is numbered according to function.
For a 12V NC relay (Normally Closed)
#30 power in
#87 power out > this will be closed and will open when the 86 is powered
#87a power out. > This will be open and will close when the 86 is powered
#86 12v actuator power
#85 ground
We have several relay kits available at
http://www.hollisterroad.com/proddet...=C4060SXL5MTFK
This will run a single speed single fan.