Your college/university SHOULD have a Placement Office, that works with potential employers to arrange interview schedules for seniors and new grads.
They're your best bet.
I have NEVER heard of an employer wanting to see major code samples for an entry-level hire. By definition, an entry-level hire has little to no work experience. The best you can hope for is a few summers of co-op experience, and some internships. Also, depending on where you co-op'ed or interned, the code may not be releasable.
In a healthy economy, a new BS from a good school should have no trouble with Placement Office interviews. (In an unhealthy economy, you're screwed, and so is everyone else.)