Upload & Sell: Off
Charles, I'm using a laptop which has an eSata port to which I have a 2.5" 500GB 5400rpm WD Scorpio Blue always plugged in. On that drive is a folder called 'Photo Master'; it contains subfolders based on subject: Animals, Plants, Vehicles, etc.
Shoot. Remove CF card. Plug card into reader. Open Lightroom. Import images into subject folders; Plants, Clouds, Landscapes, etc. Eject the card. View, Flag and Delete images in Lightroom. Back up LR catalog at each exit.
Manual back up is to two 3.5" 1TB WD Green harddrives in a USB 3 enclosure using Karen's Replicator. I do this about once or twice a week so I have three external drives with identical folder structures and files on them; I have a 128GB SSD running Windows 7 so there's no room for photos on my 'main' drive.
Regarding USB powered drives. They are almost exclusively 2.5" drives that require far less power than 3.5" drives. You need to think about capacity (2x 2TB 3.5" drives is a good start) and connectivity; USB2 or ______. Your available ports, USB2, USB3, ______, will determine what kind of enclosure you might look for and then fill it with bare drives. If I had the money, I'd go with Western Digital Caviar Black every time, but my harddrive collection has grown 'organically' and so I have many types of WD drive.