Fact: Only roughly 2% people actually cut coupons from the Sunday paper... so chances are you know somebody who will gladly give you their coupons.
As for organizing there are several ways to do this... it just depends on what works best for you. If you are in my MOPS group and were there when Blaire shared about coupons you saw a big coupon binder for the very meticulous couponer. That binder actually belonged to me. Another fellow MOPS gal has a binder much the same. I must admit I learned everything about the coupon binder from her. You can check out the binder here
Now if that is overwhelming you can do a simple envelope method that Crystal does a good job of talking about here Crystal also links to some other blogs and sites that have other ideas as well.
As for restaurant coupons (usually you find these in postal mailings or the Wednesday paper) and store coupons (like Jc Penny's, Home Depot, JoAnn's, etc.) I have a big according style binder that I keep these in. I organize them buy the type of store/restaurant.
How much time does this take? It depends on how many coupons you have and your organizational method. When I first started it took a lot longer than it does now. The longer you do it, the quicker you get. My binder takes a good amount of time (roughly 1-2 hours/week)... however it is worth it when it comes time to look for a coupon- AKA- I am not shuffling through 100 coupons in an envelop looking for those 3 Cover Girl coupons I just know I have somewhere! I usually try and cut my coupons and organize them in 1 sitting (often during the kiddo's nap time).
One other note about the time it takes. Figure what you save in a week and divide it by the hours you put into couponing... you will find that you get paid well to coupon! For example last week I spent 48$ on groceries and my savings was around 50%. So that means I should have spent $96 but because of my planning and couponing I saved $48 (50%). If I spent a total of 4 hours last week between planning/cutting/ and organizing coupons, I technically made about 12$ and hour... not bad for a part time job eh?
If you have a way that you organize your coupons and would like to share about it, please do so in the comments section!