I have been a frequent visitor of all portal sites in various category one such site that I have recently visited is madrasi.info. This site seems to be a good one with its content they give you all the details about chennai right from the various destinations in chennai upto the educational system in India. Their educational articles include various list of engineering colleges in TamilNadu, B schools and other articles such as the admission procedures for various foreign universities which will be very usefull to all the students who are passionate about their studies in abroad.
Even they give information about the various destinations in Chennai which they have categorised as arts, beaches etc. They also provide you with various delicious south indian recipe article such as vatha kuzhambu, chakkara pongal etc. Even their transport section is good with all the details about Bus, Train and Air time tables and fares. This site seems to be a good guide to the people who plan to have a visit to Chennai and to the people in Chennai.