Also with your children and dogs it is easy and safe nowadays. I cycle a lot in Somerville and Boston with my two daughters. (we are Dutch and just love to be outside and be healty and we love bikes in Holland as many know). And cycling in Boston is as safe as cycling in Amsterdam. Important is not to go too fast, behave in traffic and follow traffic rules and watch carefully.
I arrived a few months ago with my family and wanted to get around easily and safely with my kids to the playgrounds, my daycare, and to do some shopping and I did not want to always have to take my car. I just love to be outside and like to exercise. They just started selling this Dutch trendy bike which helps me to get around, so maybe you would love it as well and this will be of convenience to you as well. www.myamsterdambike.com
I attended a Cambridge free urban cycling workshop last month and they will organize it more often the coming months to stimulate cycling and improve a healthy/green environment in Cambridge. Info is on the website of The City of Cambridge. I know you also get a free helmet when visiting the workshop.