When a great deal comes along you will want to take advantage and buy as much as you can! One way to do that is by utilizing a Clipping Service. There are several and they all vary in what inserts they offer and prices. There are also companies that only sell whole inserts. I have 3 clipping services that I like to use and one insert company. I do not necessarily order coupons each week or even inserts. I tend to order whole inserts on the week that the P&G brandSAVER comes out and stick with clipped Qs on other weeks.
Coupon Dede is my favorite Clipper just because the site is so easy to use and she ships fast! I am almost always able to find the coupons I want and get them in time for a sale! She is based in Texas so the coupons get here on average within 2 (business) days of my order.
The thing I like about Kuntry Klippers is that they sell their coupons in groups of 20 one low price so when you need to stock up on something you get a great deal. Just make sure you leave enough time before the end of a sale.
The Coupon Master is a great site to get cheap coupons. I think they have the best prices and they offer a military discount of 10%. You will have to show proof (see the FAQs here), but still a great bonus on an already great deal.
For whole inserts I recommend Insert Insanity or Sunday Coupon Inserts . I have been ordering from them since May of 2011 and am pleased with the service–and being able to sleep in on Sunday and not run out in search of papers before church! The prices fluctuate from week to week based on the number of inserts, but I was impressed with the speed and it was a good price. The price per set of inserts is usually $2-$3 per set which is the same you would pay buying the paper.