I actually used to live in Quebec...so I hope I can help!!
Some high points of Old Quebec (by that do you mean Old Montreal??)--since you're staying in Laval...I'm going to assume you are going to be on the West Island, and that therefore you'd be talking about old Montreal.
(i've never been to Quebec City, so I have nooo clue about any of that)
But if you are talking about old Montreal some stuff you should check out would be the street performers, the maple syrup stand (they usually sell sugar on snow--which is THE greatest thing ever...but since it's summer they may not have it...but if they do you should SERIOUSLY try some!!)
There's also alot of really cool art galleries that are worth peeking into (but I wouldn't recommend going IN....some of the people are rather snooty) There's this store called "Mortimer Snodgrass" which sells THEEEE coooolest stuff ever, some really funny trinkets and just stuff you won't find anywhere else.
And if you'll be in Downtown Montreal at all you should really go to the huge store Simons, it's exculsive to Quebec and they have some amazzzzing clothes!!
Also check out Olgivly's....it's really posh & expensive, but even if you're not going to buy anything it's still pretty cool to look around in.
As for eating places, my FAVOURITE restaurant in downtown Montreal is Carlos & Pepes, I HIGHLY HIGHLY HIGHLY recommend it!!!
Also make sure you get a bagel from a bagel shop (like Real Bagel, Yagel Bagel, something like that if you see one. Montreal is probably next to New York on tha amazing bagel front!)
Also if you see a Lafleurs that's a GREAT place to get a quick meal, they have amazing steamed hotdogs!!
An since you're staying in Laval, you should definitley go shopping at Carrefour Laval, it's a great mall with some really cool stores!!
And make sure you get some cookies from Felix & Nortons, THE worlds most amazing cookies!!
And if Les Ailes De La Mode is still there make sure you go in!! Some amazing brand name clothes for reallygood prices.
Other places I'd recommend going if you have transportation there and a free day, check out Ste. Anne de Bellevue, it's a really beatiful little waterfront town, a great place to get ice cream and just chill and look around all the little stores.
Anyways, I REALLY hope that I've helped!! If you need any more info feel free to ask.