There are at least two different ways to deploy Service Pack 1 for Windows 2008 R2 and Win7 by using SCCM.
[Scenario 1]
Use SCCM SUP (Software Update Point) to deploy SP1 as an normal update.
Fast and Easy way but I prefer to have better control over Service Pack installations than normal Hotfixes/Monthly updates so I do not use this method my self.
[Scenario 2]
Build a normal software package with the just the Service Pack Binary and install it using quiet and unattend switches. Let the SP binary do the reboot and make sure that the program can run even if no user is logged on. Also make sure that the installation is allowed to run 180 minutes – it takes at least ONE hour to install Service Pack 1 on a fast server!
Then build a query based collection with all the systems in scope for the Service Pack and advertise the package without any mandatory time against this collection. I prefer to use Download and Execute on Service Pack Advertisements even if this uses the double amount of space.
Then pick some pilot systems in the collection and trigger the advertisement manually to see if everything works. The unattended switch shows you progress on the system console screen so be sure to connect as first user and to Console-0.
After this you can plan and schdule a controlled mass deployment of Service Pack 1 to all your servers/workstations in scope!
If you have any questions, please write a comment below!
