Writing Custom Reports in Scheme for GNU Cash

[Caoster]

I am just starting to write custom reports for gnu-cash.  I was wondering if 
anyone could point me to some specific resources.  

Also, I was wondering how i might specifically integrate the "Notes" from an 
account into the transaction report for that account. 

Finally, I was wondering if anyone out there had a number of prexisting 
reports that they could send me.  I would especially like one that can be 
used as an invoice with the "Notes" field added. 

Thanks,
Kevin