Can you incorporate a bike ride into your commute, by driving part way and biking the rest?

Stay away from mountain bikes that have suspension forks and seats. The ideal commuter bike is a hybrid, it's not light as a feather like a road bike, but there's no point making it super heavy with a bunch of stuff you don't really need because you're not going to be hopping logs and careening down mountains. But you'll probably end up with a mountain-style bike, meaning it'll have mountain bike handlebar instead of drop bars.

Tires are the first priority. Neither skinny road tires (streets sometimes have rough terrain) no knobby mountain bike tires (slow you down) are for you. You want hybrids, and if you have a little extra $$, you want a kevlar lining (armadillo is the brand I have).

After that it depends on how you'll use the bike.
Gears or fixie: do you have hills?
Rack, seat pack, backpack, rack trunk or panniers: how much do you need to haul? Consider a trailer for groceries. Look for a used kiddie trailer.
Fenders: Not necessary for fair-weather cyclists, essential for all-weather cyclists.
Lights: Will you ride at dusk or in the dark?

Once you are riding, you'll find other things you need, like a brooks saddle for your girly-bits. Try a different handlebar, such as an albatross bar, a trekking bar, or a moustache bar, for wrist, hand or arm discomfort.

Hope that helps!