The most important thing to get right when setting up your shock is to get the sag right... get that right and your 80% done, then you just have to dial in the damping settings.
So, here are some graphs showing the Suspension Sag vs. Shock Compression for each of our full sus rigs.
A lot of people think 30% sock compression = 30% sag, but that is not normally the case, it all changes due to leverage ratio curves. Hopefully these graphs I made up will help you tune your bike in more accurately.