You're plans sound good to me. I rode my bike almost everywhere I went when I was a kid. My bike offered me my first real taste of independence and it was also a great source of adventure. Although I didn't realize it at the time, my bike was also a key component to my physical development…. fast forward to middle age… I returned to cycling the year I turned 50. I realized my lifestyle wasn't particularly healthy and I decided to do something about it. I went to a local bike shop (LBS), purchased a "fitness" hybrid and started riding again (for both fitness and fun). I wish I could say that I have ridden consistently since then but that has not always been the case. I have never purchased a bike off of from Craigslist or a pawn shop. However, others who post in these forums have done so and have been able to save significant dollars or purchase a better bike than they could have afforded otherwise. My advice would be to visit some LBSs sooner rather than later and take a variety of bike for test rides. I believe you will find this very helpful, even if you are not ready to purchase a bike yet. You will be able figure out what size you need and can also start narrowing down what type of bike you really want. Then you can start keeping your eye out (via Craig's List, LBS, etc.) for a bike that fits your needs and desires. BTW, if you do find a used bike (from wherever) that you are interested in, I would strongly suggest that you take it to a LBS to have it checked out prior to purchasing it. The LBS will charge a fee for this, but it will be well worth it. My last advice is to be stay committed and keep working on your fitness. Make it a priority and (as best as you can) don't allow other things to distract or prevent you from doing what you have decided is important for your health. Best wishes and let us know what happens.