Composite Sandwich Panel Strength Estimating

Anyone know of any publications or web sites that have some
basic rules of thumb on how to estimate the strength of a
composite sandwich panel–for the mathematically challenged?
That is, for a given load, what core thickness (of what density)
and number of plies of glass or CF per square ft. (or other
unit) of panel. Case in point, I would like to use a CS panel
of approx 44" X 68" as a center segment in a hybrid chassis for
a light weight street rod. Front and rear chassis extensions
would be 1" sq. steel tube in a space frame arrangement. From my
“eyeball school of engineering” (if it looks right, it probably
is right) point of view, a core of 3/4" end grain balsa with
4 to 6 layers of CF and epoxy on each side plus some top and
bottom layers of thin plywood and 6 oz. glass as dent protection
for the CF is the starting point. Hate to overbuild as minimum
weight is the object of the exercise.

Thanks

Vectorply has free software available called vectorlam: http://www.vectorply.com/lamdesign/vectorlam_sw.htm