I don't use them much anymore, but
afullcup.com was so helpful when I was starting out. The boards are very friendly.
Slickdeals.net is great for looking ahead once you learn the ropes but they won't spoon feed you deals and the old timers are not nice to newbies who ask questions that can be answered by reading the threads/using the search function. I use
KrazyCouponLady.com when I want to get the deals quickly; they link directly to printable coupons so I can check 2 drugstores and 2 grocery stores and get the coupons I need in less than 10 min. (Scroll down past the photos on top to get to the chronological blog of deals, or click "Stores" on the top of the page, then click on the store you want to see blog posts for.)
The easiest way to save money on coupons is to make your shopping list, then go on coupons.com and print out any coupons that match your items. If you shop at Target, cross check Target.com coupons, Target mobile coupons (
TotallyTarget.com keeps a pretty current list), and Target Cartwheel.
You can print 2 of most printable coupons from EACH device (some facebook coupons only allow 1, but try for 2 anyway). Hit the Back button when it's ready to print, and send it through a second time. You will get a second unique coupon. Any device you can print from will work.