Proper shoe fit is so important.

My advice? Buy your first pair of bike shoes at your LBS. You really need to try them on. Each brand fits so differently, and within brands some models differ as well.

Buy the best-fitting pair of shoes that you can possibly afford, even if the price seems steep at the time. Remember that a good stiff pair of bike shoes can last for years.

As a new rider, you are also (probably?) going to need help installing and adjusting your cleats (for clipless pedals). This service should be free if you purchase pedals/shoes at a shop. If you bring stuff in that you mail-ordered they will charge you.

Once you find a style/brand of shoes that works for you (and you know how to set your own cleats) you can surf the web for good bargain for your second (and third and fourth...) pair of bike shoes.

Good luck!