I just went through this with my parents. In CT, we had the choice of Connecticare or United Healthcare. The way the guy explained it to me is you have Medicare A and B. That is a given and you pay for it directly out of your social security. Then you have the option to get insurance through a major health insurance place like United Healthcare or Connecticare which is Medicare C. This will allow you to go to hospitals, doctors and get prescriptions. It works just like before you went on social security, like when you were working and your employer gave you health insurance.
You can opt for just Medicare D which is just for prescriptions but reasonably it is better to go with Medicare C.
Each health insurance company had a program with lower deductibles but you had to pay a premium ($119). They also each had a program where you paid a higher deductible but had no premium.
this webpage will give you better info: medicare.gov
You only have until 12/31/10 to sign up.
One thing you should remember if you already don't know, if you take generic drugs, you don't have to have a prescription plan.
Walmart, Target, Stop and Shop, etc all give you a 90 day supply for $10.