You can use database roles to more easily manage privileges for groups of users. Database roles simplify the process of managing privileges, because you can grant privileges to a role, then grant the role to users. When you want to revoke privileges for a user, you can simply revoke role authorization from the user, rather than revoking each individual privilege.
In addition to creating and modifying roles, you can drop a role from a database by right-clicking the role in the Data Source Explorer and selecting Drop.