Much advice to give, as I did lots of it between 1996 – 1971 and 1982 – 1992.
In a nutshell, you’ll reach average speeds of between about 24 and 28mph so aerodynamics will play a far larger role than in cyclo cross. Try and adapt a streamlined position on the bike (tri-bars are a must) and concentrate on holding this with a regular and smooth pedalling rate. If your mind starts to wander, imagine that you’re in a solo breakaway from the bunch just out of sight behind you. Ideally, you should just exhaust all your energy as you cross the line without having to sprint like Super Mario within the last 100 yards. Practice will enable you to do this.
Look at some of the positions on the time trialling forum – don’t bother about disc wheels or anything too expensive. Many a good roadman has done super times on a standard road bike with just a pair of tri-bars clamped on.
Try and ride a few evening club events in your area as a ‘private’ entry for the experience – you’ll learn more from these than reading a book about it.