A shop manual is only going to tell you the factory settings. The factory settings are for what Suzuki's engineers believe to be the average weight rider riding the bike in an average fashion(speed).Slice though the above opinions and GET A SHOP MANUAL.
If you one, weigh more than the average person(and that's not a US average) or two, ride faster than the average rider rides, you need to set the sag for your weight/pace.