We use QuickBooks Pro too. My wife attended a two day class on how to fully use it. I would highly recommend attending one of these classes if you can. It was put on by Intuit, the makers of QuickBooks. My wife says the class was well worth it. She learned how to use a lot of the features we were not using in the past.
Now to answer the question I think you're asking. QB2000 will not remember different prices for different people. For example, You "mow and trim" Mrs. Smith's lawn at $45 and you do the same for Mrs. Jones at $60. QB2000 will not remember the different prices for the same "job" at different customers.
However, QuickBooks Pro 2001 will. If you enter Mrs. Smith as the customer, enter that you "mowed and trimmed", $45 will come up in the price so you do not have to enter it every time. Also I do not believe you can automate the billing, but I will try to find out.
I hope this answers your question. If you need more help e-mail me at smithf36@ytci.com
Joe