Be sure to learn how to lock your bike properly. A lot of bikes get stolen simply because the owner did something dumb like lock the bike to a short pole, or use a cable without a U-lock.

Lock Strategy

http://priceonomics.com/bike-locks/

https://www.nationalbikeregistry.com/proplock.html

If you get a bike with quick-release anything (wheel, seat, etc.), do something about that too, because the thief can just quick-release the thing right off your bike even if you lock the frame properly. This article shows how to lock your saddle if it's a quick-release saddle:
How to lock your bike - Bicycle Coalition of Greater Philadelphia