If you are raising a baby and can not breast feed than feeding them baby formula is the only other option. Brands like Enfamil and Similac are the most popular, but there are also organic brands (that are slightly more expensive). In March I found a $5 off Enfamil coupon, and have not found any printable Similac coupons BUT If Similac is the only brand you are using I know a few ways to get coupons and save money.
The easiest way to get Similac coupons is to sign up for their rewards program. They will send you $5 off coupons / certificates in the mail on a regular basis for the first few months. These will help you out in the beginning. If you are already feeding your baby Similac and need some deals right now a great way to save is buy in bulk online and get free shipping + cheaper prices
I find that Amazon always has good deals for Amazon, check the Similac page on Amazon and you will see a lot of good discounts. You can buy the dry formula in a pack of 6 to get the bulk discount and free shipping.