The most convenient method is to USE the online mode. You build your profile on the Siemens home page. Of course, you'll be given a unique ACCOUNT that provides you access to all of Siemens' various opportunities around the world.
They have a referral program where you can be recommended by an internal employee.
On-campus recruitment is ALSOUSED by Siemens to hire freshmen. It does, HOWEVER, only visit a few colleges and universities.