This protocol will work even without too much stress about determining appropriate starting paces for the workouts. If you just 'guess' conservatively about what your target and interval paces will be (for the interval workouts) or just your target/base pace (for the 'time trial' efforts) and modify based on those initial performances any subsequent sessions of those same workouts, you'll eventually approach the training zones where you need to be. But this is a bit of 'trial and error' and it will potentially take longer to get where you want to be.

So for those keen to adopt a more 'scientific' approach to training paces, I recommend using the V-dot system. I've found that the V-dot system of paces offers a pretty good prediction of ideal training paces, based on a single, initial time trial effort that can take some of the guesswork/trial and error out of the system and help maximize the return of your workouts right out of the gate. Here's how to use it.

1. Run two miles as fast as you can, and note the time. Yes it's going to hurt. Consider this the first honest effort in your walk down the One Hour fitness path. [Note: while it doesn't have to be a two mile run, I've had excellent success using this distance as the initial input into the V-dot algorithm as it seems to produce the best pacing suggestions for both longer and shorter efforts.]
2. Go to a V-dot calculator. I like THIS one. Change the distance to 2 miles (or whatever distance you ran--it'll support metric distances too for those of you not living in a country committed to ancient measurement practices). Next, enter the time it took for you to complete the run, then hit 'calculate V-dot.'
3. Examine your paces. You'll see training paces on the right, and expected running times on the left. The training paces will give you a good starting place. So for example if your V-dot was 52, your first 4x400 effort could include a target pace (time to complete a lap) of 85 seconds, and an interval time (elapsed time between starting each interval) of 2:00 or 2:15.
4. Use the threshhold paces closest to the distance you're running for base pace/treadmill pace for the time trial efforts, or for hilly outdoor time trials. Use a 'pro-rated' 400 meter interval pace for flat time trials, as a target, meaning if your time trial is 1.5 miles long, multiply the 400 meter time by 6 (~1.5 miles) to get, for a V-dot of 52, a target time of 9:06 or a per-mile pace of 6:04. Note, you SHOULD beat these paces, particularly when flat, as you'd have already run 2 miles faster!