RSS email campaign problem

Hello, I am trying to setup an RSS email campaign and I’ve been having a tough time getting it to work the way I want it to. Most of the tutorials that I’ve found show me how to send out an email with the latest post from my website but what I’d like to do is a weekly roundup of the latest content. Accordingly, I need multiple post summaries in a single email. I’m not sure what merge tags to use to accomplish this. Can anyone please help me with this and/or point me to a good tutorial?