Printing a report from a button a wizard is quite easy and very fast in execution. Its really awesome when you created a report on your own format using OpenOffice or any other report designing tool for OpenERP, and you can call that report on a single click of a button.
I created a report and sent it to server earlier, now I wanted to launch the same report using a wizard. I had to create wizard for this. my wizard folder:
print_my_report.py (wizard class)
I created a wizard, added the necessary fields, and a many2many relation as my report belongs to the invoice module(report), so that i can get a list of the invoices. Notice the print_report function that tells to fetch those invoices that fall in the given date range, then return the report name. I used my own report so I used technical name of my report. Type should always be ir.actions.report.xml.