Doc-H,
It's hard to tell you how much to save because rents can be VERY different depending on where you live (what part of the city, what part of the country)! Down here in the "minimum wage belt" my 2-bedroom, 1900sqft townhouse runs $460 a month...a pretty good deal. However, when I lived in Norfolk, Virginia our 1-bedroom apartment was $625. In places like California, New York, (any major city) you can expect to pay at LEAST twice that! Basically, you need to start looking at where you're interested in going and do a little research. As for saving up, you will need a pretty good job to do it...even at my piddily $460 a month, it would be $22,080 to pay the rent for 4 years of med-school. Better plan on loans instead!