Martin,
Since the 8253 and the 8254 chips are very similar, you can visit ni.com and make a search on "8253". Some of the results that you will get from the search will be example programs that show how to do Pulse Train Generation in LabView, LabWindows/CVI, etc.
Each example program will also have information on how to connect your I/O signals to the hardware.
Good luck with your application!