Jennifer, the Walgreens program requires you to save your receipts and send them in with the appropriate pages from the EasySaver catalog (on a rack near the entrance). For RiteAid, the easiest thing is to just go to
https://riteaid.rebateplus.com/Default.asp? and enter each receipt as you get it. After a few days (up to 10 or so), the entered receipt will change status showing what you've earned. At the end of the earning period (normally at the end of the month, or the following week), or earlier, if you've bought all the rebate-able items you plan on for that period, simply go in and request your check. Rite Aid is great as you can keep your receipt and do other rebates with it, while with Walgreens you've actually got to send in the receipt (and pay the postage). However, with Walgreens you can request a gift card. With this, they'll put your rebate amount, plus 10%, on the gift card each month...so it pays your tax and the postage.
I've saved literally HUNDREDS of dollars this year using these 2 programs, and we are fully stocked with free hair products, toothpaste/brushes, air fresheners, etc....
Good luck getting started!

You'll only regret that you didn't start earlier!