Dabolim Airport in Goa is well-connected by air, rail and road to the rest of India. Regular flights from Delhi, Mumbai, and Bangalore airports are available on all major Indian carriers, tickets for which are available online (see this links below). Seasonal international flights also operate to Goa. If booked early enough, air tickets are extremely affordable.

The International Centre is 45 minutes drive from the airport. Taxis are freely available at the airport, and transportation arrangements can be made through Centre as well.

By train, one can travel to Goa from Mumbai on the Konkan railway. Karmali railway station is closest to the Centre.

Panjim, the Goan capital, is a 15-minute drive from Dona Paula.

Here are some useful travel links:

Air Travel:
Indian
Jet Airways
Kingfisher Airlines
Go Air
Air Sahara
Spice Jet

Rail Travel:
Indian Railways

Road Travel:
Paulo Travels