After some research, I recommend the following procedure:
1) First click on the recipe card so that you get the best resolution possible, then drag it onto your desktop or do the right click thing and save it to your desktop.
2) Upload the jpg recipe card to your photo center of choice. I've found that having the recipe cards processed as pictures, they have much better resolution than if I were to print them at home. I'm all about the pretty, believe me.
3) Order the recipe cards as 5x7 prints. They were not created as a standard print size of 4x6 and they will not conform to that size. You will lose part of the recipe cards if you print them as 4x6s.
When I get my 5x7 recipe cards back from the photo center, I adhere them to a 5-1/2 x 8-1/2 inch piece of card stock (half a full sheet), and slide it into a sheet protector of the same size for durability. Sometimes you can find the sheet protectors at your local office supply store, but I order mine in bulk online through KeepFiling.com.
UPDATE: You can also just laminate your recipe cards, which I recently started doing. Go here to read about it.