I agree...too early to worry about accessories, especially racks. Your downhill commute to work means a backpack will be fine for now.

Do consider a bike that CAN take a rack (and even fenders) in the future.

The advice above about a big gear range for your climb home is critical!

Test ride a lot of bikes at bike shops. Since you say you are a newb, it is hard to get a bike on Craigslist that will meet your needs unless you are willing to patiently wait a long time.

Are you SURE you are going to stick with it? If not, you may want to spend less than $1000...maybe $600? If you dig it, you step up to a better/funner bike later.