Begining analaytical methode validation

hello all;
can any one show me how to choose weight and dilution for begining analytical methode validation
a whole of our methods of swab analysis began by 20mg/100ml solvent, x1/100 ml solvent, and i am now performing analytical methode for new product…how much ml have I to use for swab recovering study.(100cm2 stainless steel)? or wich concentration have I to use…?
Iam a begener and I am not familiar with analytical methode validation…so I will be gratfull for your help…
thank you very much.