The courses and requirements are described on the bulletin here.
The "Intention to Complete a Certificate or Minor" form can be downloaded from the Registrar's page here; it should be filled out, signed by me, and submitted to the registrar.
If you would like to see what other courses offered in a given semester can count towards the minor, you can use the "Linguistics Electives" attribute on the banner course search, as described here.
Please contact me with any further questions about the minor.