Have a look at the websites and hope that help. I went there in June this year.... food is really nice. We went to a few temples (snake temple is not really worth seeing nowadays), the botanical garden, the Penang Bridge, etc.
Public transport is not very convenient there so may be a good idea to live close to town. If you are going to catch a cab, make sure you find out how much first before you board to prevent being overcharged.
It will be easier if you have friends there who can take you around and show you the nice place to eat. When I was there in June, we ate on the stalls on the street most of the times and if I didn't have friend there to reccommend me the place, I wouldn't have gone in myself. They look rather unhygenic but the food turned out really nice. Thank God I didn't get sick either.
Also, try to avoid wearing any expensive jewelleries and carrying a handbag as there are many robbers around.
Have a great trip!
Attraction and what to do: http://www.visitpenang.com/sights.html
Accommodation: http://www.penang-hotels.com/