People seem to have extremely strong opinions about him, but I can't really tell why. Was there some event he was famous for that gave him a terrible reputation?
Kissinger is a specialist in European diplomacy, here he was all for subtle diplomacy and was all for advocating human rights.
Read his book [1], i can only recommend it; it is a fascinating study of how peace was restored in Europe after Napoleon Bonaparte, the system worked (mostly) for almost a century ! One if his great achievements is restoration of US relations with China, another achievement was the Helsinky accord of 1975; actually the Human Rights part was used as the document that legitimized Eastern European and Soviet opposition groups of the seventies and eighties.
Now when it comes to other parts of the word he was not quite as diplomatic, this leads to accusations of double standards. No problem with encouraging the 1973 Chilean coup d'état; or with the coup in Argentina in 1976, most of Latin America ended up being run by the military, not without his help; no problem with dragging Cambodia into the Vietnam war; another conflicts of interest is East Timor. In all these far away places he was not quite a champion of Human Rights.
[1] Kissinger "A World Restored: Metternich, Castlereagh and the Problems of Peace, 1812-1822" http://www.amazon.com/World-Restored-Metternich-Castlereagh-1812-1822/dp/0395172292