(All recommendations are from Lye Tuck-Po, with help from Geoffrey Benjamin)
Whilst getting ready for your trip, here are some books you can dip into (most are ethnographic, based on fieldwork in or near Penang):
From this list, Khoo's Streets of George Town is probably the most useful for a short-term visitor. It's jam-packed full of information about the streets and placenames. A little bit outdated now, but still a fun read. Widely available in Penang bookstores. (NB: Khoo [AKA Salma Nasution Khoo] is also the driving force behind—among many commendable achievements—the Penang Heritage Trust and the publisher of her book, Areca Books. Areca have an online service as well as physical premises in George Town that you can visit.)
Jenkins' urban anthropology of heritage debates in George Town provides valuable insight into the 2008 UNESCO listing and anticipates problems that are still unresolved.
For fiction, especially for first-time visitors to Southeast Asia, an absolute must-read is Amitav Ghosh's The Glass Palace (2000), which weaves fiction with history across practically most countries in the region. At heart, it's about the Indian immigrant experience, especially those parts that almost never enter standard history books. From the memorable opening in Mandalay onwards, it's utterly absorbing—it's the sort of novel that one stops to talk about, years after reading it. Anthropologists, take note: Amitav Ghosh may be better known for his literary gifts, but his beginnings include a D.Phil in Anthropology.
Open on my table right now is Peter Carey's My Life as a Fake (2003), set partially in Penang. It's pulling me along, but without much intensity. The classic set-in-Malaya fiction was Anthony Burgess' Malayan Trilogy (the first novel in the trilogy, Time for a Tiger, came out in 1956), drawn from his experiences as a schoolteacher here during the Emergency period (1948–1960). I've got the iBooks version on my iPad—may take some more years to finish reading it. Funny ha-ha, though, what little I've swiped through so far.
If you prefer to get your advance previews from the "pictures," the Hollywood movie Anna and the King (1999) and the recent British Channel 4 TV series Indian Summers were shot partially in Penang. Ang Lee's Lust, Caution (2007) includes location shots in Ipoh, two hours away. Much, much earlier, the film version of South Pacific (1958) was also shot on location "here" but far away—Tioman Island on the east coast. These are the memorable examples that come to mind quickly. There are others, most of them execrable, including a 1970s caper with David Niven and the horrible tropical fantasy Sleeping Dictionary (2003), shot in Sarawak.