For your science manuals
There are a lot of manuals for employees of Aperture Laboratories. But you don't necessarily have to read them. Being honest here. We used to hire smarter folks, but our death turnover rate is so high that we've had to lower our standards to the less-than-literate. But here's your Employee Manual and the various books on radiation poisoning that the government requires us to give all new hires.
But really, don't bother reading them. It's not necessary to do your job. Just follow Cave Johnson's voice and you'll be fine, okay? Take these bookends, they'll hold the books up. Why yes, they do look exactly like a test subject going through a portal on one side and out the portal on the other. Pretty clever, isn't it? Now let's get you off to your first testing assignment - I hear you're in the control group.