OK, my general rules are to use about 1/2 the diameter as the "plunge"
depth, and maybe 1/4 the diameter as the step-over. I reduce the
feed when "plowing" the tool at the full width, as the first pass at this
depth, then pick up the feed on additional passes at that depth.
Feed is calculated by RPM x number of flutes x diameter of end mill.
So, for 2800 RPM x 4 flute x .25" diameter x .010", you get 28 IPM.
(The .010 comes from my McDonnell-Douglas slide rule that gives .010"
for a 1" end mill in Aluminum, and says to multiply feedrate by tool
diameter.)

These numbers may be upper limits, and you need to reduce them when the
workpiece is delicate or not rigidly fixtured. I generally reduce the feed
when plowing to 1/2 to 1/3rd of the feeds calculated by the above method.

Jon