new users are at least a three step process:

create the user in Active directory (you said that was done)

create a login for the user in SQL Server(you said that was done)

Create a user in the database to match the login(missing?)

Assign the appropriate permissions/role so the user can access data(missing)

--creat the login for the Active Directory User

CREATE LOGIN [mydomain\NewUse] FROM WINDOWS;

--switch to the right database: if more than one database, repeat for each one

USE SandBox;

GO

--Create the user to match the login

CREATE USER [mydomain\NewUser] FROM LOGIN [mydomain\NewUser]

--assign permissions

--put the user in the correct permissions role

exec sp_addrolemember 'RoleAlreadyCreated', 'mydomain\NewUser'

--an example in case you don't have the role with the right permissions yet:

CREATE ROLE [AlmostOwners]

EXEC sp_addrolemember N'db_ddladmin', N'AlmostOwners'

EXEC sp_addrolemember N'db_datareader', N'AlmostOwners'

EXEC sp_addrolemember N'db_datawriter', N'AlmostOwners'

--can the users EXECUTE procedures? comment out if false

GRANT EXECUTE TO [AlmostOwners]

exec sp_addrolemember 'AlmostOwners', ' mydomain\NewUser'