Exploring the delightful maze that is Powell's City of Books could easily take up an entire day in Portland (maybe even a night, depending on which rockstar author is doing a free reading upstairs). And, thanks to the obscene amount of used (read: dirt cheap) literature on offer, you'll have plenty of funds left for good eating nearby. My list of suggestions is by no means exhaustive, but I tried to cover most of cravings you may get while browsing, because let's face it, you're going to be in there a while.
Go to Oven and Shaker for higher-end, wood-fired pizza (try the one with garlic scapes and goat cheese) from James Beard award winner Cathy Whims. Order the Pepper Smash, a refreshing cocktail made with the juice of bell peppers and aquavit, to wash it all down.
Sizzle Pie is perfect for a fast lunch or late-night pizza eating. The spot has a bit of a punk rock feel (mostly coming from the jukebox), with dirt-cheap combos like a slice and a huge salad for $6, or a beer and a slice for $5 at happy hour. Try either the classic Ace of Spades (pepperoni) or the vegan Spiral Tap, which features caramelized onions as sauce.
Little Big Burger is Portland's answer to In 'N Out and Shake Shack. Their compact five ounce burgers, cooked medium-rare, are the perfect fuel for book-hunting.
If you happen to be nearby on a weekday for lunch or happy hour, try Gruner's ridiculously juicy burger, adorned with bright pink pickled onions and smoky-sweet Nueske's bacon.
Visit the 9th and Alder Cart Pod for the classic Portland cart experience. Grab a melty sandwich from Grilled Cheese Grill, spicy squid noodles from Noodle House, a hefty Gyro from Aybla, light and crispy fish and chips at The Frying Scotsman, or slow-cooked porchetta from People's Pig.
Go to Parish to grab a dozen fresh, briny oysters and a plate of fries. Order the Comeback sauce for dipping fried things in, and any of their cocktails with Cynar.
Head to Kenny and Zuke's for late night pastrami fries and classic Jewish deli sandwiches as big as your head. Come during happy hour to avoid the ferocious brunch line. On a cold day, try their earthy Hungarian mushroom soup for a lighter but satisfying option.
Clyde Common is probably the most "Portland" restaurant in the area. The big, open space (attached to the artsy Ace Hotel) has communal seating and a view of the always-buzzing bar. For more intimate eating, ask for a table upstairs. Don't leave without trying any of their seasonally changing housemade pastas, the squid ink fideos appetizer, the barrel-aged Negroni (or bartender Morgenthaler's eggnog with sherry in the winter).
Head a few blocks into downtown for Bailey's Taproom, where they have 24 rotating taps listed on an electronic beer board which tells you exactly how much of each beer is left so you can appropriately plan your next move. One Bailey's perk is that you can order greasy drinking eats from next-door Mexican joint Santeria.
Visit Stumptown in the Ace Hotel for people watching and serious cups of Joseph. Any espresso-based drink is a safe bet, which is nice since an expertly crafted espresso is the ideal accompaniment to a good book.
Hit Nuvrei for delicate macaroons in every Easter egg color imaginable, or big chewy chocolate cookies to nibble at one of their window seats.
Head up to SW 12th avenue to Ruby Jewel for customizable ice cream sandwiches, homemade ice cream, and frozen yogurt. Try the Blazers Sundae, which has Oregon huckleberry ice cream and toasted hazelnuts.