Welcome Barry, I'm sure you will find great insights from many helpful people here as I have.
Here is a link to the 5 Step Approach.
http://paceandcap.com/forums/showthread.php?t=5715
There is a section on projecting pace. When practice races are posted in this forum, check the pace projections of the other matchers and see how they came up with them. Post yours as well and ask for feedback. It won't take long...