On Wednesday, July 13, 2011 12:25:48 PM UTC-7, jtpr wrote:
I am making drawer fronts and want the edges to be completely rounded over. The wood is 3/4". Now, I have a 3/8" radius bit

If you set the bit depth less than 3/8", you can put a curve where there
was originally a (roughly) square edge. That means your inevitable dents
on the drawer edge don't draw attention.
If you set the bit depth exactly 3/8", it'll not look good, because
any small bending of the board will make the edge of the
cut waver noticeably (you can sand away this 'feature', of course).
If you set the bit depth more than 3/8", it makes a shadow line
at 3/8" where the bit cut stops. Sometimes that's attractive. With
an undersize pilot, you get two shadow lines (good for outside corners
of upright members, but maybe not a drawer face).

I'd discount the 'completely rounded over' look, myself: it looks ugly to me.
Are there any particular drawers you DO like, and can copy?