saving iPhoto photos on a Flash Drive

Hi, I want to save all the photos that I have in iPhoto now on a Flash Drive. Because these photos are going to be straight from the camera, they are going to be very large. Do you recommend that I crop and size each one before saving? some are paintings, and I would want to save them on my computer as large files for printing on Giclees. Those specific photos I could save to Desktop, open in Photoshop and save them in a picture file on computer. But the rest of the photos don't have to be large as most are reference or snapshots. Question is, do I resize them and then drag them to the FlashDrive window? Thanks for any help available. I also need info on the entire lot of photos that are imported at this time in iPhoto, to know how much space they will take up in the Flash Drive.
Sucer