I think you need to do some research before going for an affiliate program.
For selecting affiliate programs with Datafeeds you can go with CJ, shareasale and other networks.
Once that is done you can also get ready made datafeeds scripts from sites like:
http://www.datafeedfile.com/ and
http://mydatafeedscripts.com/
And if you are a programmer and want to develop your own script then you can develop one like I did it here at
http://www.latestgirls.com
For affiliate links on your parked domains you can use the links generated from this networks that you have joined and paste that linking or banner code on your parked pages.