Lets learn out about the TOLKAPPIYAM and TIRUKKURAL at http://omtamil.org/tolkappiyam-introduction/ and http://omtamil.org/tirukkural-intro-part-1/
Here's an introduction to AGATHIYAR NIGANDU or the Nadi at http://www.youtube.com/channel/UC7ka9_ZPCMRMt8U1ikhvb8w/videos