Heres a couple of links regarding cadence...
http://www2.bsn.de/Cycling/articles/cadence.html
http://www.beginnertriathlete.com/cm...?articleid=433
I went up from 76 to 88-90 range. Uphills depending on lenght I try higher rpm. Find it to be actually more efficient . Some spinning trainning might help you move your cadence up..... god luck hope it helps a bit