I run an ecommerce website but I've just realized that I really don't "know my customer". But I don't even know where to begin when figuring out the demographics of my average customer. How does a small business with limited resources conduct marketing research? How do I begin to find this information? Where do I look? How do I figure out her wants? Needs? Income? Spending habits? What does she read?

I have no idea where to start... Help!