Q: how to set up HP3510 airprint on IPAD?

Check the "Notes" and "How to print in iOS" sections of the HT4356 article you attached above.

Setup AirPrint Printer

1. Buy an AirPrint enabled printer; see list below

http://support.apple.com/kb/ht4356

2. Run the CD provided and set printer and iPad on the same network

3. Start printing from your iPad using AirPrint

Troubleshoot Airprint enabled printer

1. Turn off router, printer and iPad

2. Turn on router and wait 30 seconds

3. Turn on printer and wait 30 seconds

4. Turn on iPad and test printing

There is nothing to set up on the iPad. Once the printer is set up properly the iPad will find and print to it.