^ That's a nice list. July is easily the best time to visit Quebec City (unless you don't like tourists, you won't be alone here!) I would add
The Charlevoix region (
Tourisme Charlevoix) which is Northeast of Quebec City, past the first 3 places jambo posted and on the way to the Saguenay. Very scenic with quaint villages (Les Éboulements, Ste-Irénée) and an arty small town (Baie-Saint-Paul, a little over an hour from Quebec City).
Early July (10 days from the 1st Thursday in July) is the Festival d'été de Québec, Quebec City's music festival.
Accueil - Festival d'été de Québec
The festival is immensely popular here. Getting passes for the whole festival at the stated cost ($65) is impossible if you can't wait in line in early May, but $25 day tickets are available except for the biggest shows (this year, Elton John and Metallica were blacked out, which still left Ben Harper, Black Keys, Dropkick Murphys, Simple Plan, Martha Wainwright, Coheed and Cambria, Buddy Guy, John Fogerty, Death from Above 1979...)
There are many many restaurants for every budget in the central parts of town. Obviously depends on what you're looking for but here are some of my favorites -- SSS (Simple Snack Sympathique), Poisson d'avril, Le clocher penché, Aviatic Club, Les frères de la côte, Enzo Sushi. There are exceptions but most of the better deals (quality/price) to be had are slightly off the beaten path or in not overly touristic neighborhoods (Le clocher penché is the best example though it's by no means far away from anything else).
The Image Mill (Le moulin à images) is an impressive architectural projection (pictures, animations, movie bits) on a grain elevator in the Old Port, mostly depicting the history of Quebec City but also has stuff on all of French Canada and Hurons (First Nations present in the QC area). It's free and it runs daily Tue/Sat at dusk (so around 10 PM in July).
There's also a daily, free Cirque du Soleil show called Les chemins invisibles. I believe it changes yearly and will be in town until 2013, in an urban setting (a concrete jungle really). By all accounts it's not as impressive as 'real' Cirque du Soleil shows, which we've also had in the summer in Quebec City since 2008, but I'm not sure if those are going to be back.