Security track

Ok, I've made a decision I want to pursue the security track at my company. My boss has my full support and we both discussed starting with the Security +. My question is once I start with the Security +, where do I go from there? My company is supportive that they will pay for the proper training, but I also want to study and learn on my own. So anyone in the security field can give me some advice once I take the Security +.
To give you more info, we are running Windows 2000/2003 network. No Novell or Linux. I want to present a project plan to my boss as soon as I know the route I want to take. Any guidance would be appreciate. Thanks!