Hi Bobby,
Welcome to the forum!
You can create "Custom Field" for new fields. Please follow the link for details
If you want to show your custom fields in standard print formats, keep "Print Hide" unchecked while creating custom field. Also you can uncheck that for standard field from Customize Forms.
In print format, you can access values of current document using doc.fieldname, check Setup -> Customize Forms for fieldname. And for different utility methods, please check existing print formats.
We are working on developer documentation, there we will try to cover it in detail.
Thanks,
Nabin Hait