[wayner]

1) stay away from department store bikes

They are heavy, carry blingy looking components to entice you, but sacrafice quality for quantity
Difficult to maintain

2) if you are looking for a multi speed bike, educate yourself on group sets (gears and brakes)

That's usually the difference between two otherwise identical bikes

Avoid anything with components made out of cheap looking tin stampings ( just walk through a department store and a bike shop for visual cues

3) buy used name brand or new lower end name brand
Do this once your know what you are looking at