Apart from the survival stuff that everyone else has neatly captured, I would search for pieces of information about the previous occupants. It would be quite like putting together a jigsaw puzzle to figure out what they were like based on the contents of their house.
Of course, I say that from the comfort of my home! Maybe I'll just get the essentials and run in a situation of actual danger.
It is what you read when you don’t have to that determines what you will be when you can’t help it.
Soap, deoderants, toilet paper (because the struggle is real!), medicine, alcohol, shoes that fit me and clothes! Anything that would enable me to hold on to femininity!
"And will you succeed?
Yes! You will, indeed!
(98 and 3/4 percent guaranteed.)
KID, YOU'LL MOVE MOUNTAINS!" - Dr. Seuss
I think I'd look for essentials: food, clothes, medicine, anything that can help in survival. Although if I came across a discarded paperback novel, I'm pretty sure I'd find some hidden place in my rucksack for it...
Edit: oh, reading the previous poster's comment...how could I forget...toilet paper!
I'm a huge fan of video games where scavenging and looting are how you survive. In a post apocalyptic situation the most important things to find would be food and medicine. I would also look for useful tools, but still try to keep your load light.
I'd look for food and water first. Then perhaps I'll search for any object I can use to defend myself in case I'd need to. Afterwards, I'll find a place I can use as an emergency hiding spot.
I feel like finding an untouched house would have so many possibilities it would be hard to carry it. I might stick around for a few days and enjoy some of the stuff that would be too hard to bring with me. But definitely anything durable and light would be coming with me - clothes, personal care items, hopefully a couple of books.
I would defintiely look for necessities like clothes or weapons. Food and medicine, unfortunately, usually do go bad after a time, so I would only take them if I knew they were still good. The sections with the Traveling Symphony were set 20 years after the plague, so most medicines or foods would have expired a long time ago.
On the other hand, I would definitely look for new shoes, particularly tempting books, and things that reminded me of my old life.