I bought a little academic planner from Nike at Walmart to use as a training log. It’s inspiring because it has dates of all major league, college and olympic sporting events in it. But the very next day, I found something better!
Check out Beginner Triathlete, it’s got an easy to use online training log in a blog format. Enter a few workouts and you can start to graph things like training volume, distance, speed, weight, heartrate, etc, etc.