Kanchipuram does not have an airport. The nearest airport is Chennai, which is about 50-60 kms from Kanchipuram. Daily flights are offered from about 20 Indian cities.
Airlines serving Chennai include:
Air India www.airindia.in
Go Air (*) www.goair.in
Jet Airways/Jet Lite(*) www.jetairways.com
Kingfisher/Kingfisher Red(*) www.flykingfisher.com
The budget airlines are denoted by a (*). All of them are very good. They sometimes offer excellent rates when booking far in advance, but you can easily book the same day and get a very good rate.
For a one-stop comparison of flights check www.cleartrip.com or www.makemytrip.com. I'd recommend booking directly with the airlines though in case you need to change your travel plans. I have had occasion to change my dates and have never had any hassles and never been charged any fees.
From Chennai, the roads to Kanchipuram are very good. The drive in a private taxi will take between 1-2 hours depending on traffic. If you plan to return to Chennai the same day, make arrangements for the driver to take you Chennai-Kanchipuram, from temple to temple, and then back to Chennai.
The main temples are spread out and it's best to take a rickshaw when going from temple to temple. The driver will wait for you and take you to the temples or you can hire a rickshaw at each temple. Make sure that your trip is metered or negotiate a price before you get in the rickshaw.
At the travel desk of the Taj Connemara in Chennai -- a magnificent hotel -- I arranged for a car and driver to take me to both Kanchipuram and Mamallapuram (Mahabalipuram). On the way to Kanchi we stopped at the impressive monument to Rajiv Gandhi, erected on the grounds of his assassination.
Cost for the full day (in an air conditioned car, before tip): just 1500 rupees, or well under US$40.
To getting Kanchipuram ,can go by bus,or train.Its 70km from Chennai(Madras).Neasrest airport is Chennai.
From Chennai ,tamilnadu tourism gives daily trips to Kanchipuram.
If going by bus,to sighseeing can take taxi or auto(3weeler).