I've been commuting by cycle since early 2011, but recently took a few months 'off' cycling when we had a baby and I was working odd hours. Just got a new job myself, and I want to start cycling again. It's a 12 mile round trip, downhill going, uphill coming back (a killer!) and I have a hybrid. A road bike didn't 100% suit me and I have a mountain bike I found on a landfill and restored and I wouldn't dream of commuting on).

One massive piece of advise I'd like to give is 'know your frame size'. Try tons of bikes. Find one that's comfortable and go with it.

Other than that, a good multi tool and a few spare tubes have been my best friends since I started cycling. Never looked back really.