Hi Andy,
Welcome to this Microsoft Project newsgroup
After you've entered the data, hover the mouse over the bottom left corner
of the cell ( a little black X) until the cursor turns to a +, click and
drag down through all the children. This will fill down.
FAQs, companion products and other useful Project information can be seen at
this web address:
http://project.mvps.org/faqs.htm
Hope this helps - please let us know how you get on
Mike Glen
MS Project MVP
See
http://tinyurl.com/2xbhc for my free Project Tutorials