There are three ways to print a report for the new reporting module.
If you want to print to a printer that’s accessible from the client, but not the gateway, you will have to have a report component in a client window, and call report.print() on it. That should call up a print dialog where you can make your selections.
If you want to print to a printer that’s accessible from the gateway, you can use system.report.executeAndDistribute(), or you can schedule a print action. Both of these will use the paper size you defined in the report (so be sure that the printer you select has that paper size available.) To set the paper size, open the report’s workspace, select something in the report, and then click back onto the report itself in the project tree. The property inspector will let you set paper size, margins, etc.
The width and height units are points, no matter what units you are using for your paper size.