I wish you and all the others in the area the best in the next few days during Hurricane Irene. Since you are 3 miles inland, you should be okay from the flooding from the ocean, although you will need to ensure that you are prepared for localized flooding, especially if you are in a lower lying area.
The key thing is to prepare like you were going on a 5 day camping trip and be prepared with any items you could think of that you might need for that period of time without any "conveniences." Have plenty of water - you do not necessarily have to go out and buy bottled water but collect water into containers in your home that you can have on hand in case your local water supply becomes contaminated. Fill your tub with water before the storm hits to use as "gray water" - to flush toilets, etc. This would not be your drinking water but used for other water purposes.
Have enough food and supplies (emergency battery powered radio, flashlight with extra batteries), first aid equipment, etc. If you take any prescription medication, be sure to get that filled to have extra on hand.
The main thing is to be prepared that if there is major damage in your area, the emergency services may be overwhelmed and you will need to rely on yourself. Since you are in CT, it should not be as bad as lower areas (like NC), but with hurricanes, you can never fully predict what their power and track will be.
All the best as you prepare to ride out the storm. Below is another Website with some additional information that you might want to look at:
Disaster Preparedness Checklist from NOAA