The downside of touch interface is that the iPad screen gets covered with finger prints, oil smudges, and germs. Apple doesn’t recommend using window cleaners, household cleaners, alcohol or aerosol sprays to clean iPad screen. The iPad screen is coated with a oleophobic coating that helps make the screen fingerprint proof. Using the household cleaning cleaning products may damage the coating and increase the number of fingerprints on the glass.
To clean your iPad screen from finger prints and smudges use a soft, slightly damp lint-free cloth but be sure to not let any water or moisture in any of the iPhone openings. Be sure that no dust or small particles of dirt are on the screen.
The best option to disinfect an iPad screen is a high concentration rubbing alcohol. While Apple doesn’t recommend using of alcohol occasional disinfecting may be worth that trade-off to you. Quick googling reveals substantial anecdotal evidence that it won’t noticeably harm your screen in small doses.
Another option is to get a screen protector and use the above alcohol disinfection method. Screen protectors cover up delicate oleophobic iPad screen coating freeing you up to use pretty much any cleaning products you want.
Also iBarrier – a disposable sleeve that can be used to cover an iPad.