You might find some stuff here:
http://www.oncolink.upenn.edu/
A hint on using Google for this sort of thing (I hope you're using Google): if you're looking for government information, you can target your search by including site:.gov in your search string. If you're looking for academic sites, include site:.edu in the string. These will get you straight to good information.
If you're looking for individual folks, you might be able to find some names if you follow links from the U-Penn oncology site. Having worked with and for academics, I can tell you that most of them are very busy and generally aren't very helpful even when they're not.
Really, though, this is a great opportunity to sharpen your web-searching skills. Just remember to always cite your sources, and make sure it's something reliable. Being a .edu or .gov site is a good indicator; .org sometimes is, though a lot of nonprofit advocacy groups whose objectivity is highly questionable turn up there, too.
Your question so far is a very broad one, and oncology is a very broad and technical field -- maybe it would be easier to offer pointers if you told us what exactly your assignment is, and what your grade level is.