Ouch! You did what many of us have done and broke your collar bone. This plan is your 6 week comeback to training outside again. Day One of the plan starts on the day you get the green light from your Doctor to ride the trainer. This is usually about 3 weeks after the break if it is mending on its own or 3 weeks after surgery if you have a plate and screws inserted.
I pulverized my collar bone in February 2007 into so many pieces my surgeon couldn't count them. I have my own titanium plate with seven screws.
This six week plan is on the trainer. After six weeks with the go-ahead from your Doctor training outside may begin again - yeah! At that point move on to another plan specific to your distance or category.
You can get a lot done and build up real fitness on the trainer if you spend the time wisely. Rules for this plan are: (1) You must have medical clearance to exercise on your trainer and (2) everything you do must be pain free. If things hurt, pause the plan or start over until your body is ready. If your collar bone is failing to heal, training will be fruitless and probably cause more harm than good. Fix your bones first, train second.
Visit the LW Coaching website http://lwcoaching.com/ to ask training plan questions on our forum, read mountain bike specific training articles, learn new workouts and see what events our coaches and athletes have been racing.