My husband and I are traveling around Europe for the next 6 months (tight budget) and want to do the month of November in southern Spain. We have found some examples of inexpensive apartments to rent from homelidays.com around Marbella, but were wondering if we would be able to travel to other surrounding cities without a car during our month stay. How is the public transportation in that area? Reliable, inexpensive, fast, etc.? How long does it take to ride a bus to the Malaga airport? How much does it cost to take buses and or trains to other cities? Any advice would be helpful. Thank you!

For Malaga Airport there's a rather good train line running along the coast to all the major tourist ghettos like Marbella

So this coast is mainly just touristy?

I also have always traveled without renting a car, though I have never had the luxury of one month in one place. I spent less than 2 weeks in Andalucia, but I can tell you that beyond the main cities, a rental car is best. You need to check distances (try viamichelin) for the the specific places you are interested in.
My suggestion would be to pick four places and stay in each one week. Breaking it into 4 mini-regions may work out better for day trips, which aren't always convenient.
Try andalucia.com and google for some bus schedules to get a better idea.
Fodor's is great, but I also suggest you post at Lonely Planet's Thorn Tree forum because there are some really helpful Spanish experts on there.

It is very touristy. YOU can find
inexpensive places all over Spain
in November. I agree with Yorkshire.
Break it up into 4 weeks. If you just
do the coast, you won't have seen
Spain.

Yes the coast is touristy, but well, you're a tourist. There is very good bus service and tour companies for daytrips to Granada (for example). There are also places on the coast that are beautiful, and not as touristy, Nerja, Gibraltor and cadiz to name a few. The real advantage of a car is you can go to more then one place in a day and don't have to wait for your ride home when you're ready to leave. It's very easy to drive there.

Hire a car. I spent a lot of time waiting buses and trains.

train does Seville and Cordoba very well from Marbella/Malaga