Creating records with file upload in migration

I have a migration which creates several records along with the table.
eg
Forum.create :title => "General Discussion", :description => "General
Chit-Chat"

I am not sure you want to combine migrations with record creation. It
is probably best for you to handle this via a load script or a rake
task.

As to the file upload, if you are using a plugin like attachment_fu,
then you are all set. Take a look at the plugin tests directory to see
how those simulate the upload of files and create the uploaded files
either in the db or in the path you specified in your models.