If you don't want to spend much on a bike, look on craigslist for a used bike. I've noticed large bikes tend to be a little cheaper due to less demand.
You can look at bikesdirect.com but they take decent drive train components and throw in cheap everything else for the most part. Decent quality but you always get what you pay for in the bike world I'd say. A real bike shop is probably a better option in my opinion but don't get sold something you don't want there.
Personally I think "hybrid" bikes are usually a crappy option. Most are just mountain bikes with smoother tires.
If you are riding on pavement in mostly ideal conditions, I'd avoid these things:
1. Shocks (Your legs are way better shocks than anything on a bike)
2. "Gel" or excessively squishy seats
3. Steel (I love steel bikes but anything new made of steel is going to either be a piece of garbage or prohibitively expensive most likely.
4. Disc brakes (Rim brakes are cheaper and have worked perfectly fine for decades.)
5. Step through frames (Just makes it heavier. If you can't physically get on a standard bicycle can you really expect to ride it very far?)
6. Tires widerthan 28mm
7. Looking only at the number of gears (more gears isn't necessarily better)
Things to look for:
1. 700c wheels (standard wheel size, 26" wheels just don't have a good selection of pavement tires in my book)
2. If you want a rack, the frame should have the mounts. (This is a commuting bike after all)
3. Aluminum (cranks, wheel hubs, wheel rims, rear derailleur will always be aluminum on an inexpensive but still good quality bike)
As always Sheldon Brown is a great resource
http://sheldonbrown.com/articles.htmlI thought Bakari's guide to buying a bike was pretty good too
http://biodieselhauling.blogspot.com/2012/01/buying-bikes-from-craigslist.html