If you’re new to biking and in the market for a bike go to your local bike shop and talk to them. Test ride a few bikes, but don’t buy that day. Let it sink in and do some more research. Once you decide what to buy try to buy local. If you’re confident you’re all-in buy new, if you're not so confident or are on a tight budget try used. Please use caution, but craigslist.org is a great way to get a deal. bicyclebluebook.com will tell you what a used bike is worth.