Is it alright if we charge the iPad overnight?

Yes. You can also turn the device off (Power button for 10sec, then slide to power off.) Do that after you put in the cable.

It's okay. When it's fully charged the charging circuit will cut-off.

Yes there's no problem at all. Also there's no problem if you don't charge it fully and then use it, which is another misconception.

trishav96 wrote:

Is it alright if we charge the iPad overnight?

Yes.

Ipad Battery... About Best Practice

http://www.apple.com/batteries/ipad.html

As well, all other iDevices can do the same.