Need to drill long hole

[Doug Mason]

What is the best method to drill long and straight by hand? I've got the extra long bit--so a dowel jig is probably my best option for straight drilling?

[Richard Butler]

What I did was to take a 4x4 and place that on the drill press and drill a hole through it. Then I clamped the 4x4 to my workpiece and drilled my hole using the 4x4 as a drill guide. It worked quite well.

What are the dimensions of the hole you need to drill?