Roxanne is 13 weeks old and we are walking abou 30-40 minutes every evening. She actually put her foot down (litterally) when I first started at 9 weeks, but I worked with her and now she loves it.
Plus, we started puppy pre-school, and they suggest that you have your puppy drag a leash through the house until they are out of the puppy stage. The puprose of this is to be able to control them... when they are ripping up your oriental rug... just step on the leash, pick it up and take them to a time out, such as tieing up to a door. Using the leash through the house should help to your puppy to get use to the collar and leash.