Hip2save.com and passionforsavings.com are two of my favorite sites. I also love the krazykouponwoman.com. I think I spelled that right.
Target has great printable coupons and there seems to be no limit to how many you can print or if there is I haven't hit it yet. I combine them with manufacturer coupons and get amazing deals. I have learned to not use them right away. Everyone is trying to use the weekly coupons that week, but they don't expire for weeks and sometimes months. I have learned to be patient and just keep a close eye out on the sites I mentioned above and watch for the prices to drop and the deals to come.
Walgreens has great printable coupons that you can combine with manufacturers coupons as well as Walmart and Whole Foods.
Ohhh and Pathmark (don't know if you have this store in CA) offers TRIPLE coupons up to $1 every Saturday and Sunday. They will triple any coupon up to $1 even if the coupon states "Do Not Triple or Double". You can only use up to 10 manufacturer coupons per day though. I get amazing savings this way plus free stuff like Pantene, Mr. Clean, Febreeze......
I am really lucky that I live in a NYC apartment building. I don't ever have to buy the Sunday paper for coupons. Every Friday a HUGE bag of circulars and coupon books like Redplum, Smartsource, P&G, get placed in our lobby. As far as I know, only one other tenant takes them. The bag is full all week, plus we have a connecting building and they receive a huge bag as well. That is where I get multiple coupons. I just bring up as many bags of circulars and coupons that I can.
I really don't use coupons for food items. When I do it is for things like Truvia, which I get at Pathmark with a tripled coupon and get a box of 44 for $0.99. I have tons of Truvia coupons.
Sign up for store cards that when swiped make sure you get the lowest store price. Stop and Shop, CVS, Rite-aid, Walgreens.......
I could go on and on, but you really should check out the sites I mentioned. I found hip2save through a recommendation made here on Mamapedia. The other sites I have found I Googled. "coupon sites"
Good luck. Have fun. It is quite addictive. Especially when you buy $55 worth of goods for $19.26!!! LOL. I'm clearly not as extreme as those people on the show.