Maybe you could start from here:
http://www.cdc.gov/STD/HPV/STDFact-HPV.htm
but I guess that if you want less basic description, you will have to go quite deeply into the links…

I forget the specifics, but find a list of the proteins encoded by HPV (there are only 9-12 or so) and look at the function for each. I think there are two viral proteins that inhibit two different cellular tumor suppressors, p53 and retinoblastoma. Epithelial stem cells infected with HPV will not enter the lytic cycle (although their differentiated descendants will, for some reason that I forget) but instead will express these viral proteins without dying. Infected epithelial stem cells will replicate faster and with lower precision because these two tumor suppressors are non-functional. Together these two effects allow the accumulation of errors that could lead to cancer.