SABRE Dorm/Apartment Security Alarm Kit
This package should be all you need for the basic home and personal alarm stuff.
It includes a door stop and a window alarm. You stick one piece on your window and the other piece on the window casing, and when they move away from each other the alarm sounds.
This can be used on a door as well.
And you get a personal alarm keychain with a pin activation.
Remove the pin and it screeches at over 100 decibels. You can take this with you to your next apartment too.