1) Create Read_Only Role And Give the Access of Viewing any Definition.

    USE master
    GO
    Create role Read_Only
    GRANT VIEW ANY DEFINITION TO Read_Only
    USE master
    GO
    Revoke VIEW ANY DEFINITION TO Read_Only

2) Create Role and Give Execute Role

    Create role DB_Execute
    Grant Execute     to DB_Execute
    Revoke Execute  to DB_Execute

3) Create Role And Give Alter Role

    Create role DB_Alter
    Grant Alter     to DB_Alter
    Revoke Execute  to DB_Alter

4) Create Role And Give Insert,Update,Delete Role

    Create Role DB_Write_Database
    Grant Insert,Update,Delete to DB_Write_Database
    Revoke Insert,Update,Delete to DB_Write_Database

5)If you want to Create Read-Only Definition to All DB_User expect Admin Role.

    USE master
    GO
    GRANT VIEW ANY DEFINITION TO PUBLIC
    USE master
    GO
    Revoke View Any Definition to Public