I saw someone say get a road bike, depending on the streets, I'd recommend a mountain bike. After a month the weight of the bike will be nothing to you anyways, so having a stronger frame is nothing but a plus, especially if you want to hop curbs or go off road. Not to mention road bikes make you feel every bump in the road, where as a mountain bike usually has better suspension by way of shocks.
I recently got a
gas bike, after getting doored by an old lady, and my hour commute is now about 20 - 25 minutes depending on the hills. I live in SF Eastbay so the speed limit gets up to 30 at the most, and my bike can do 40 on a flat, with 150 to the gallon. I don't need a license or insurance, but I do have a couple nice motorcycle helmets for it and a lot of heavy duty locks. My bike cost a little over $2k, the price of an electric bike, but it's twice as fast and has better range.
As far as commuting itself,
I'd recommend blinding lights and staying in the middle of the road as much as possible, especially if you're just going to go for a regular pedal bike. I bought
turn signals for night, and a
loud bicycle horn to stop drifting assholes. Other than that, if you're in the bike lane, watch through the back windshield of cars to see if someone is about to make an attempt on your life.
And in all cases, brake instead of go if you ever have some kind of car scenario involving intersections or blind spots, not worth getting hit over.