This US Forest Service Web page, How to Prune Trees, explains the why, how, and when; and has diagrams to help guide you. Lest you get carried away by the power of a good pruning saw, they offer this caution: under 5 cm diameter - go ahead; between 5 and 10 cm diameter - think twice; and greater than 10 cm diameter - have a good reason.
Tool or Gardening Product
At a recent garden show I made the mistake of handling a pair of rose gloves, and they soon were accompanying me home. In my daughter's parlance, "These gloves are sweet." Made by West County Gardener, they are a supple, 100 percent synthetic suede that's puncture-resistant and durable, and even machine washable. They have a long gauntlet for extra protection, and they are great-looking, too! Take a look at them -- and the other styles they have available at: http://www.westcountygardener.com/gloves.html