I don't think there is a link addressing the printing issue specifically. So this is definitely a good question. I haven't started mine yet, but I did put this thread up about a couple of really good sites for diy pocketfold invites. The first one tells you how to do it, however, it is in Publisher. The other I don't recall what it specifically said since I wasn't making the actual folder (that website shows how to make the folder too).
But, if you don't have Publisher and the second site doesn't say. I can only suggest printing 2 inserts on one sheet of 8 1/2 x 11 paper and test how it comes out. The website for Cards and Pockets suggest you can use 3.5" wide or 4.75" wide inserts. So if you did the 3.5" you should be able to get 2 on one sheet. I hope this is a little help for you. Good Luck! I'll search around and see if I can find something for you just in case!
http://bestdestinationwedding.com/forum/t21405