Configure labels and title

histo->GetYaxis()->SetLabelSize(.1); // font-size of Numbers on axis in percent of ??? 
histo->GetYaxis()->SetTitleSize(.12); // font-size for title in percent of ??? 
histo->GetYaxis()->SetTitleOffset(.2); // distance between axis and title in percent of normal distance
histo->GetYaxis()->SetTitle("mySweetTitle");