Travelling to Mexico City business trip 6 months?

I am travelling to Mexico city from India for 6 months.
1.What are the good cheap accomodations (not hotel but apartments and like) available in Mexico city
2.Ideally wish to stay alone in the room or apartment which should include atleast facility for basic cooking, refrigerator, microwave
TV and an internet connection 24x7
3. What are the place which can be visited during weekends
4. Are there any Indian communities (people from India) concentrated at some location.
5. Is it advisable to deal in USD or Peso

The best way is to find an apartment, it should be by somebody who works on that.
Mexico City is not a safe place, my recommendation is to find a god area to leave.
The best way to expend money in Mexico is with the peso.
There are a lot of place to visits in near to Mexico City you can start with the Museo de Antropologia e Historia, Pyramids de Tenochtitlan, Pyramids del centro historico, Centro Historico, etc. You will not believe how much option Mexico has for visiting during weekends, I am sure ta ht you will love Mexico in the 6 moths that you will live there.
about the other questions I don't know.

A nice cheap basic hotel is Casa Gonzalez (click the link to read reviews from other travellers) You can use that in you first week as a base camp while you search for an apartment. Many apartments are not advertised in the paper--ask your business contacts if they know of any. You may just be walking down the street and see "Se Renta" in an apartment window.Click the second link below to read about 279 things to see and do in Mexico City.
And there are Indian restaurants in Mexico City--check them out for information on the Indian community.

Not sure if there is a community but you can check this link to have some info on the indian religion temples, which even if you practice a different religion I'm sure they will be able to help you a little better than us in how to adjust life in Mexico city.

http://en.wikipedia.org/wiki/Hinduism_in_Mexico

I think everyone answered alot of your questions, just want to advise you that craigslist.com also is up for Mexico City so you can check that out for apartment listings. There may not be much, but it might help.