There are a lot of options. Having cleaned and cleaned my original 1g iPhone constantly for the first few weeks after iday I pretty much stopped cleaning my two next iPhones and now iPad. My tshirt does the job to suite my needs.I use a clean dry microfiber cloth to clean the screen, that's all you really need.
That's not really true. If there is a coating on the glass that could be removed over time with things like Windex. That's why you should never use Windex on anti-glare surfaces on televisions. Repeated use can eventually do away with it.It's glass man. Anything that is ok to clean glass is ok to use on the iPad.