Chief considerations? Above all else, remember that it is just riding a bike. You've just asked a bunch of addicts about their favorite recreational drug. The responses you'll get will likely make this seem way more complicated than it really is.
Having said that here are the things I would think about
:
Are you going to ride in your work clothes or change when you get there?
How much stuff do you need to bring with you? Just yourself? Lunch? Clothes?
If you need to bring stuff with you, what are you going to pack it in ? (backpack, panniers, milk crate on a bike rack, etc)
If you have a mechanical problem (like a flat tire) what's your back up plan ? (fix it, lock it up and hop on a bus, carry cell phone, etc)
Do you have a good lock and/or a safe place to keep your bike at work?
It sounds like you don't do much riding on roads so I would suggest taking a practice ride to work on a weekend or something to at least familiarize yourself with the route from a cycling perspective.