I monitor 1saleaday.com, they have 4 deals everyday.
For discount coupons, I use retailmenot.com, they have saved me a lot of money.
In addition, when I shop through major internet retailers, I make sure to first go through my loyalty rewards programs website first. This way, in addition to the points I get using my credit card, I get rewards points from my loyalty program. (If the retailer has its own loyalty program [staples, eBags, AE; ect], I hit the trifecta)