You have to verify
1) The sale deed and the prior deed (Check whether any minors interest involved)
2) Latest Tax receipt and encumbrance certificate.
3)Possession certificate, Location plan and sketch from village office.
4)Whether the land being involved in any developmental scheme or restrictions under Land Aquisition Act, Reforms Act ,Costal Regulation Zone Rules etc.
If you are purchasing in a residential area you can verify it with local village office.If you intend to purcahse a vast area for evelopment you have to verify all the aspects completely.