We send out larger sized emails to our clients, and choose from a variety of documents. Is there a simple way to use salesforce to create labeled checkboxes and reminders?
No. Checkboxes are fields, which need to be defined in the object. You could use Workflow Rules to create Tasks for these followup tasks, or to send the Email to the clients, or to set a field to true (such as 'needs to get a mailing').