December - March is the best time to be in Mumbai. The weather is great and airline prices are also reasonable after Dec 25th.
If you are flying from the east coast - tri state area, then Continental has a direct, non-stop flight to Delhi from Newark and Delta has a direct, non-stop flight to Mumbai. Love those new Boeing 777 ER/LR 200. Very soon, Air India will acquire these planes are begin flying direct, non-stop as well.
If you are cost concious, then these direct flights have created opportunities for you as well. Lufthansa, Air France, British Airways flying to Mumbai with a stop in Europe are feeling the pressure. There are deals to be had.
I sincerely hope that reading snippets on this Blog will provide you insight into the life in Mumbai. Mumbai -- India as a whole is a tough place for an uninformed traveller. Knowing what's going on will allow you to participate in the enjoyment of the host country. Diversity in India and Mumbai is unique. The idea is to celebrate it and appreciate the gusto with which the city lives.