The Dynamics GP Contract Administration module and the Sales Order Processing Module are connected in such a way that you can easily create new service contracts from sales orders. So if you sell a product that regularly has a service component associated with it, and you would like to use Contract Administration to track and invoice that contract, this is something you should look into.
From a sales order you can specify that you would like a new contract created to manage the service contract. When the related invoice is posted a new contract will be created that has the customer information already in it, and individual line items for each item you sold. You can set up the system to automatically price the contract if you want.
Once the contract is created, you can take advantage of all the functionality within Contract Administration, e.g. scheduled invoicing, deferred revenue recognition, contract renewal, etc.
This is a video that shows the Contract Administration and Sales Order Processing functionality in action.