I would second Baxter's advice to do a drive-by. My testing center is about 2 hours away, so I didn't drive up there to find it before the exam…and I was pretty much crying in my car when I couldn't find the stupid place on exam day! The building-numbering was very weird and confusing where my exam center is. I had pretty much given up and went to turn around, and due to traffic, the only place I could find to turn around was somewhat out of hte way…and then lo and behold, there was the Prometric center, in a place I never would've thought to look, based on the address, GPS, etc.
For going to the library after your exam, I would suggest bringing just the materials you need (book, notebook, and pens or whatever) and putting them in a bag or something. The lockers at the testing centers that I've been to were big enough to hold a textbook, but probably not the extra space taken by the backpack.
I like to arrive early. With my 2 hour drive, I never know what may happen between here and there, and I hate to be late or almost-late to anything! So for most of my exams, I've been there around an hour early. My next one is at 6pm, and I'd rather not test that late, so may get there a couple hours early and hope I can get in early. 🙂 And…my last one I broke the early rule – I had an interview that morning that took longer than expected (which is probably a good sign, and I got the job which is good, but it delayed my start), so I arrived more like 20 minutes before exam time instead of the recommended 30 minutes or my preferred hour. 😉 If you're there at least 30 minutes early, you'll be fine…and honestly, you could be closer to scheduled time and still be OK. But, being there extra-early won't hurt anything either. Just bring something with you to either distract you or do some last-minute cramming in case you have to wait. 🙂
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