oncology hopeful

Hi guys. I've really been enjoying reading the posts here on AN.
I'm starting clinicals next semester, and I already know that I want to work in oncology. Everyone seems to think I am crazy. My sister is a critical care nurse and thinks that oncology will be too depressing. All the other nursing students seem to want labor and delivery or peds positions eventually.
I don't think it would be depressing to work in oncology. It's such an interesting area in terms of the science, plus I would get to help people who are fighting for their lives.

Will you guys help to break it down for me, what the different areas are in oncology that I could eventually work in? I've noticed people mention BMT, chemo, and other things. What would be the focus of these particular positions? And, are there any areas that are more likely to hire a new grad?

Thanks!