Penang is an Island which is mainly visited for its food and beach-activities.
On shore you can go for parasailing, jet skiing, massages & more.
The better area to eat drink and evening walks is Batu Feringhi.
Over here you can get fabulous cheap dinner meals starting from 7pm.
Try the hawker-centre "Long Beach". You won't regret having dinner here!
During daytime you can do some excursions hroughout the Island.
Some recommendables are the Tropical Fruit Farm, the Kek Lok Si Temple, Wat Chayamangkalaram, and some others.
For all of the excursions or so you can use the Public Transport.
It's cheap & has airco. Great connections with the populair areas.
Also visit the more traditional part of Penang. You can find them in Georgetown.
If you have money to spend for your stay, try Golden Sands Resorts.
The breakfast is great. The restaurantstaff gave overall the best service, don't expect anything special from the staff at the reception. Make sure you get a Seaview room!