@pearl hits a point - ride every day for an hour and get back to us in a month. Something along those lines.
In your OP you say you have this:
* an hour before/after work
* unlimited weekends
My math says this is 10 hours available on weekdays and say 6 on weekends. You don't have an issue with hours. Some things:
* if you ride an hour before work, it will be lower intensity just because it's harder to do
* after work is better but you can fall victim to the "man I'm too tired" monster
* try to ride 3 days a week minimum
* mountain bike on Saturday
* longer road ride Sunday
Your Sunday ride should be your "litmus test" so to speak. Add roughly 10% every week to your long ride. 1 hour, 1:05, 1:10, 1:20, etc etc. You can add 5 minutes, or 15. Don't go in this progression: 1-2-3-4-5-6 hours. By week 6 you will be in the "what beer are you drinking" thread.
You have a lot of places to start. In the saddle is the best one.