Kingjjx,
The best way to save the items is to use a database. Create a db for mailing lists and set up a dsn so that cf can find the database. Create 1 table for user info, probably just email addresses and an auto_number (identity seed on sql server) id field.
Next you want to create a table for each mailing list, this table should have an autonumber id field, and a numeric userID field (this is where you will store a subscribed user's memberTable.id).
When someone want to add themselves to a mailing list, check the user table to see if that email exists, if it doesn't then add it.
Get the membertable.id value for the email address.
Next, look into the table(s) that realte to the mailing list(s) which they have selected to see if the memberid already exists in the list table for each list that was chosen, if it does not, then add it.
Basically, the same thing for unsubscribing, check to see if the memberID is in the list table, if it is, remove that record.
You can do this without the member table, just by inserting the email directly in the mailing list table, but this is not a normalized database design, and some people tend to flail about verbally when you do not normalize a db.
Hope this helps,
David Giffin
Davtri Interactive Design