The British Cycling website has a whole load of useful stuff on there about commuting (both bike/train and bike only)
It's probably worth doing a dummy run one day, work out the route, how long it'll take, what the roads are like etc when you're not pressed for time. That way when you start riding it for real, you'll be prepared.
Worth too sitting down with an A-Z, Google Earth/Streetview and possibly some sort of bike-mapping app and seeing if you can find a quieter route, maybe part off-road? I have two routes; a dry/frozen off-road option and a rest-of-the-time road route although I can mix and match them a bit.
10-15 miles is a nice distance, reckon on approx 1hr in city traffic. Always carry a couple of inner tubes, pump, waterproof and lights. Other than that it's surprisingly easy how quickly it becomes a normal part of your day and you'll soon work out options for leaving kit at work, when/how to swap clothing over and so on.