Ok...I am BY FAR not an expert. But from what I have read and experienced on my "TT" training (on the trainer) here is all I can offer...
1. Warm up quite a lot first. You should be breaking a sweat at least and getting your legs past that initial point of where they feel a little heavy (if you ever feel that). I can tell when my legs open up in warm up. I get kind of a tingly flush feeling run down my legs.
2. Don't go out too hard. It seems when you are all revved up for the TT it's easy to go out too hard and blow yourself up early. The best TT efforts I have put in (again I've never raced except against myself on the trainer) are where I started out at a pace that I was absolutely sure I could hold for the whole TT and then as I get into a rhythm start to up my cadence from 90 to 100 to 110 or so if I feel good (although some days pushing a bigger gear at lower cadence feels better, or switching back and forth some). The power graph (if you had one) would look like an incline where the power output is greater at the end of the race than at the beginning to the point where you are suffering, but able to hang on in the last part of the ride (for me the last mile or so of a 10 mile TT).
3. I find it, many times, easier to increase my power output during the ride by increasing my cadence rather than mashing a higher gear. Although sometimes I'll mash a little to try to bring my HR down with a lower cadence. Of course that depends on your riding style. You may naturally be more of a masher. I was looking at some TT profiles the other day of some of the top pro riders. I don't even remember who or where I saw them (some link from BF). I found it interesting that one top rider averaged like 110 rpm, while the other (I think the winner) was more in the 90-95 rpm range. Different styles to acheive similar power.
4. Of course, aerodynamics will come into play. Find yourself as aero a position as you can possibly hold for the entire course. You may be a bit sore when you are done. Of course, doing my TT test on the trainer, I have not had to address this part yet.
5. I have never raced (yet). I have just been studying it. If someone else who knows more about this than I do comes in and corrects me I will not be offended in the least. Just trying to help.
6. Let us know how you did. I am very interested to see results of beginning racers as I may be interested in trying my had at it some time in the future (I still have some work to do though
7. See step 6.