When you attempt to restore your database SQL Server will perform a safety check to eliminate the possibility of overwriting your database unintentionally and fail the operation if the database already exits. Because of this safety check you have two alternatives to restore you database:

1-       Let the restore operation of SQL Server re-create your database from the backup in one step. If you take this alternative you don’t need to create the database in your new server.  SQL Server automatically will create and restore your database.

Use Enterprise Manager as follows:

Right click on “Databases”

     Select “ALLTasks”

Select “Restore”

On “Restore Database” dialog box

            type your database name

select “From Device” radio button

in Parameters select “Select Devices”

in “Choose Restored Devices” dialog box, add the complete path and the file name of your backup

select “OK”

select “OK” again  

2-       Create your database before the restore operation and disable the safety check to complete the restore operation successfully.

Use Enterprise Manager as follows:

Right click on your database

     Select “ALLTasks”

Select “Restore”

On “Restore Database” dialog box select “Options” and then select checkbox “force Restore over existing database”

 Go back to “General” on “Restore Database” dialog box

select “From Device” radio button

in Parameters select “ Select Devices”

in “Choose Restored Devices” dialog box, add the complete path and the file name of your backup

select “OK”

select “OK” again  

Finally, as Derrick suggested if you have backups for your master and msdb databases use them to recover the logins, DTS packages, jobs, alerts, etc. If not you have to recreate them manually as follows:

-          Create the logins

-          Synchronize these logins with the database users

-          Create DTS packages, jobs, etc.