Career Path

I need help in figuring out the steps I should take in my career choice. I'm currently taking a web app course and studying ruby on rails right now. It's really challenging but fun to learn. First off, I already have a Bachelor's degree in Biology and enjoy programming. But programming is so broad that I'm confuse on what to focus on. I think dealing with web application is great but I don't know where I should start. I guess what I'm asking for is what kind opportunities are out there that deal with web app and what are the things I should learn and become and expert in to guarantee me a job once I'm done with school? I need advice and guidance. Thank you.