Keeping a Swim Log
You have gone to the trouble of making a plan for your swim training, so it makes sense to keep track of how it's going. Are you meeting your objectives? Are there some areas of the training that need extra work? You won't be able to answers these questions if you don't keep track of your activities.
That's where the swim log comes in. After each session, you should record the workouts you undertook, how long it took to do them, and how you felt overall. You did buy that watch that tracks your laps and splits, didn't you? You will gain confidence if your log reflects that you are swimming your laps at a faster pace.
It's tough keeping separate training logs for swimming, biking, and running. Does anyone sell an all-in-one triathlon training log?
Yes, there is such a thing as a triathlon training log, with spaces for each daily workout in each of the three sports. It's a lot easier managing one log. You should be able to find one at your local running store, bike shop, or swim shop.
Using your training log, you can keep track of your workouts, with notes about your progress or lack thereof. With proper notes, you can even discover the source of an injury. For example, you might not know why shoulder pain keeps cropping up on certain days of your swim workouts. You might be able to correlate that pain with a specific drill and discontinue it until you recover.