First create a product in Catalogue > Products > Manage Products to link the Symphony product to.
Then navigate to Catfish > Symphony > Symphony Products and click Add New

Once you have written the name, description and defined the link to the product you first created click Save.
You will then be directed to the page below;

Here you have the first set of options enabling you to edit the product to suit your specifications;
BatchMode - The options for data upload, single allows for upload of a single entry whereas batch uses file upload for multiple records. Both can be used on the same product

SingleFormDefinition - Allows you to select which Data Types are used for the form given when BatchMode Single is used
SingleFormFindAddressMapping - Allows you to select which address fields are used in the form given when BatchMode Single is used
Skip datagrid preview after upload - Once data has been uploaded you will be directed to a page previewing the data and columns used. It is recommended that skipping this is only used for Single form
Actions
Actions currently come in three variations; Print, Email and SMS. Adding an action to a product creates the editable product for use within the definitions you have set above, for example; Example Product is a newsletter that has an email action attached. When a customer purchases Example product they can configure the action to their specifications (depending on the level of control you give them - see Action Options below) and then send it whenever they specify in the trigger section (see below). This allows for multiple actions per product which enables the customer to create anything from a text message to a one-stop cross-media marketing campaign.(Below is a partial screenshot of three actions on one product, these are shown as tabs in the editor to simplify switching between actions)

Action Options
Email
Allow the user to modify the template - Allows user to edit action
Allow the user to modify the subject line - Allows user to edit the subject of the email
Allow the user to modify the sender address - Allows user to specify a 'sent-from' address
Include a link to view the message online - Enables view as webpage
Embed images smaller than 10kb - Enables a limit on embedded image size
Embed all images - Embeds all images
PAF Validation - Used for validating addresses against a stored postcode file
Print
PAF Validation - Used for validating addresses against a stored postcode file
Hotfolder ID - The print folder this action is sent to upon completion of purchase
SMS
PAF Validation - Used for validating addresses against a stored postcode file
Allow user to modify template - Allows user to edit action
Allow user to modify the sender number - Allows user to specify a 'sent-from' number
Triggers

Triggers determine when your actions are sent, 'Now' sends the action as soon as the order has finished being processed, 'On' allows you to specify date/time and 'Repeat' allows you to resend at specified intervals
Once all of these have been configured you have created a Symphony Product!