For VLC, you just go to File -> Open Capture Device, but remember that the latency (lag) is very bad with VLC.
Yes, the long end of the USB cable (the one with 2 wires coming out) is the one that has power+data and should be connected to your computer.
We have experienced issues here with Macs under 2 conditions
1) some USB cables do not seem to work. With those, sometimes PhotoBooth detects JeVois and selects it as the camera to use, but then says on the screen that there is no camera connected. This is fixed by using a high-quality cable such as the one we included with the turnkey kits. To see whether this is your problem, maybe try a cable from Best Buy or such.
2) The Mac does not like some combinations of video modes (in videomappings.cfg) and then just refuses to use the JeVois camera although it is detected. This now seems to be dependent on OSX version. On El Capitan, the videomappings.cfg provided in the SD image works fine for us, and selects 640x480 YUYV, but it flips the video horizontally (at least in PhotoBooth), so we have also flipped the video for that mode. We just tried it on an older Snow Leopard Mac and it looks like 640x360 YUYV gets selected (and we did not flip it for that mode, since this is the one that gets used by default on Linux). So far, the included videomappings.txt seems ok, so please try first without editing it. 640x480 should always work. Maybe try it in MJPG output, this mapping:
MJPG 640 480 15 YUYV 640 480 15 JeVois Convert
3) To check if your JeVois is alive and well, you can also open a terminal (in Applications/Utilities) and type:
screen /dev/tty.usbmodemXXX 115200
(replace usbmodemXXX by whatever comes up when you type tty.usbmodem[TAB])
Then type 'help', 'info', etc and see whether you get some answer, which would indicate your camera is working well.
As far as seeing disks show up when you connect JeVois, so far we have not implemented this in JeVois, because exporting the JeVois SD card over USB would require that we lock all the files on the SD from the JeVois CPU as long as you are accessing them over the USB link. That is, it would essentially freeze JeVois operation to allow you to access the SD contents. This is to avoid inconsistencies between file operations made over USB vs made locally by the JeVois CPU.