Two-Stroke Oil Premix

This page gives very basic information as a general guide.
http://www.dansmc.com/pre_mix_ratios.pdf

rctek.com Fuel to Oil Ratio Chart
http://www.rctek.com/pdf/fuel_to_oil_ratio_chart.pdf

Wikipedea on 2 stroke oil
http://en.wikipedia.org/wiki/Two-stroke_oil

Choosing an Oil for Two-Cycle Engines
Specifically for ultralights, but a well-written guide.
http://www.theultralightplace.com/choosing_oil.htm

Two-Cycle Premix Ratio Calculator
http://www.speed-sports.com/more/oil.html
http://www.scooterhelp.com/genmaintain/mix.calc.html
http://www.mopedriders.org/html/manuals/gasoil/oilfuelcalc.htm
Fuel - Oil Ratio Calculator 
Oil Ratio Mixing Ratios

Sachs 301 fuel mixing
http://www.spartamet.org/english/e_brandstof.html

See also:
Troubleshooting