I would start by placing an image (scan) of the form you have to print on to in position and print... just as a guide. You may wish to break the image up into sections which you place in each part. This will help with approximate positions of the major elements.
The body section will need special treatment if showing more than one record... but it should help with the Top & Tail - Header & Trailing Grand Summary.
Once you have made it work at this level... you can delete the images or set the bits to not print.
PS. hold down your option key (on a Mac) while you drag the body parts around so it allows you to move them above the template.
Thanks for the tip, the scanned image might be helpful. I'm not sure I understand how to go about the body section though. How can I specify that the body should only be from 3" - 8.5" from the top of the sheet, if there are multiple records?