The easiest thing to do would probably be to begin by searching in your school's online databases. Using search terms like "stem cell research" and then narrowing it down with "stem cell research treatments" and "stem cell ethics" and so on, should help you find out what information is available in each of those categories. There's little point in deciding what "specific things" you want to include, if you cannot find any articles to cite with regard to those specific things. I think it's always best to start with some initial research before deciding too specifically in which direction your paper will go. After all, you must cite your sources, so you want to make sure the sources are available! :-) After you have done a little reading on those sub-topics, it should become clearer as to what aspects to include in your outline.
I hope this helps!