If you do go with a basket, watch out: it's a bit unwise to put a lot of weight on the handlebars. It makes your center of gravity high, and can make it hard to steer. Panniers don't have that problem.

As for reflective vests, they all well and good but they're not enough to ensure your visibility if you're riding at night. You really want front and rear lights for that; fortunately, you can get cheap lights with 3 LEDs that are fantastically bright and last for eons for pretty danged cheap.

All this said, yay biking! Riding to work makes me so very much happier than taking public transit. Not to mention that if you get into the habit, you can save a surprising amount on STM passes.