Having Business Cards Made

I would like to get some ideas for preparing a file to send to Vista Print (or elsewhere?) to have business cards made. I would use one of my photos. What is the best way to downsample to that tiny size? I could do that during the export in Lightroom, or downsize in PS CC. Or should I let the printing lab do that? How about sharpening? Once it is downsized should I select Sharpen For Print when exporting from Lightroom? Thanks for your help.