sighting

Hello all, I want to know if anyone has advice on sighting in 30yd, 40yd, 50yd, etc. pins? I recently upgraded my basic sight. The issue I have is it's difficult to be steady enough to get accurate feedback on how I need to adjust my pins. I have a ballpark idea on where they should be set...

Where is the best place to take an air rifle to get in some target practice and sight it a scope? I live in San Bernardino and wanted to know if there is a good area just go to take care of this myself. Also, if I'm going for rabbit, how many yards would you guys recommended to scope to?