There are two (actually three Apple has its own, but we wont get into that) protocols reader devices use to communicate with the computer over USB.
1) USB Mass storage: In this the storage area of the device is exported as a block storage (like an external disk) to the computer. It gets assigned a drive letter in windows, and mounted in OS X/linux.
2) Media Transfer Protocol (MTP): This is an abomination developed by Microsoft that most newer android based devices use. It is much slower and more flaky than (1). In it your device will show up as a "Media device" in windows and not show up at all in OS X (and might or might not show up in linux).
calibre supports both protocols. For MTP devices there is no dedicated driver needed, all devices are handled with a single MTP driver in calibre. So any MTP based device you use should be auto-detected in calibre.
Unfortunately, MTP implementations in many devices are very flaky. They often fail when sending files to the device. Sometimes it is because the device's screen is locked and you have to manually unlock the screen before it will work, sometimes it is because of bugs in the device, which are usually triggered by sending the same file to the device repeatedly (as calibre does, to maintain an on device metadata cache).
So if you get a communication error for your device with calibre, try:
1) Make sure the device is not screen locked
2) Reset the device
If neither of those work, then you are out of luck and you have to try using one of the wireless methods to connect to calibre, described here:
http://manual.calibre-ebook.com/faq....kindle-fire-hd