Welcome to SDN! Don't feed the trolls.
The 4.0 GPA and community service should go a long way for you. Also, you mentioned that some of your service has been medically related...I'm not sure what kinds of things you did, but you probably have some clinical experience through that. (If not, it's worth the effort to get a volunteer job that's clinically related or shadow some doctors ASAP! I think the big hole in my own application was my lack of clinical experience.) Definitely make sure you can get strong letters of recommendations from people who know you well...go to your professors' office hours, for example, and develop a rapport with them.
The research issue is difficult to say much about. It looks like you're building a pretty strong application profile as it stands, so you may not need research experience. However, if you want to get into an MD-PhD program or a very competitive, highly ranked school, research is important to consider. I would only do it if you definitely want to and have a sincere interest in the issue being studied...don't do it just because it might help you get in.
As for the MCAT, start studying early and look into taking a prep course if you think you need it. If you don't want to do a full course, definitely buy the books and study on your own. Take lots of practice tests too...and definitely time yourself so you aren't thrown off by the time limits on the actual MCAT.
On the issue of choosing schools...10 is actually quite a low number. Most people apply to 15-20 schools. If you keep up the GPA and ace the MCAT, you should be able to apply to a few less than that, but 4 is definitely too small! The generic advice is to apply to all your state schools and also choose a mix of "safety" schools, good prospects, and reaches. Looking at the average GPA and MCAT of the first-year class (see the MSAR or USNews for that) really helps a lot. But the big lesson that most of us applicants learn is that no school is really a "safety" school, and the process can be pretty random.
The only issue I see in your application right now is that you're a single mother...adcoms might question whether you can balance the responsibilities of med school and raising a child. Keeping your GPA up is one way to demonstrate that you can. Also make sure you can respond to anything an interviewer might ask about that...for example, think about arrangements for day care and school. But to be honest, I'm not completely sure how adcoms look at single motherhood, so maybe someone else around here can shed some light on the issue.
Props to you for thinking about schools and things so early (since you'll be applying in over a year from now)! It seems like you really have your act together.
