Very Basic Button Question - Pull up or down?

Is there a preferred initial state to work with momentary push buttons? Should I set the input pin high with internal pull-ups and wire the other end of the button to ground or set it up opposite to leave the pin low and wire the button to the (+) voltage rail? For debouncing - is one method preferred?

People usually prefer to use the internal pull-up resistor, one less component. I don't think contact bounce is affected by how it is wired.

The internal resistors do indeed save components as David says, but they could have been pull-DOWNs just as easily at design. Have a look at Reply#8 in this thread which gives a rationale for preferring pull-UPs.

Also the logic is easier to remember: when the button is "low" physically, ie pushed in, the line goes "low" too.

Also, there no internal pulldowns.