I'm members of MANY discounted sites for clothes and toys for the kids. Now I've only really ever used Babysteals, but they are all legit and have awesome deals. I get their emails so I know what's on sale for the day and what not. It's a great way to save on things you already buy for your kiddos.
Mamasource: Deals on places and events, in your area.
Zulily: Deals for kids, moms, and babies.
EcoBuys: Environmentally friendly deals for you.
Plum District: For moms, by moms.
Babysteals: One of my favorite sites, they have two deals, 9am and 9pm (mountain time). This is where you can get things for 60% off!
Kidsteals: Similar to baby steals, just deals for older kids.
Scrapbooksteals: A site for all your scrapbooking needs.
Shesteals: A site just for moms.
Finally....a site where you can compare or "crawl" the web for the lowest price on things!