Dubsado functions primarily around projects. We recommend setting up leads or jobs first. New clients can be added within the project creation process, as well as adding existing clients to projects.
The client section or ADDRESS BOOK is a great place to look back on all projects you had with that client. The address book is meant for just informational purposes. Contracts cannot be sent to clients through the address book, rather they must have a job applied to them and you can send the contract through the job or lead!