Is this decent, or should I be doing more? I plan to up it eventually.

My parents recently bought a recumbant exercise bike (sp I think thats how you spell it), and every day (sometimes twice a day, in the morning and the evening, or really whenever I'm bored and have nothing to do) I'll do 4 miles on it. I can usually do that in about 15 minutes.

Next week, I want to go for 20-25, then eventually I want to go for 30 min.

I also have a treadmil I'll occasionally walk/jog for 20-30 min on (its still snowy here) but I kinda like the bike better lol.

that is a great starting point. i started slow with my daily workout, and now find myself adding time or weight or whatever to it weekly. it gets so much easier to go longer or harder after you have conditioned your body. then you reach a point where the "normal" workout doesn't feel like enough, and you add something, etc

Yes, excellent! Do it!

Jay