Depending on what technology you have available, and your own preferences (as well as administration policies) you can be more snail-mail oriented or include other tech like Skype and Facetime. This is an experience even my more reticent students have been quite engaged in every year. I hope your learners enjoy it as well!
In the zip file download I have for you over at Teaching FSL, there's a parental permission form, instruction sheet for students to use with ePals, a peer editing handout I used, and also some tracking tools that will be handy if you teach multiple classes. I included the PowerPoint presentation that I created for a Professional Development session when sharing my experience with other teachers in my district.
I'd love to hear your students' reactions to this learning experience!