I won't be long - just wanted to mention a couple of things. The point is that you'll definitely need a USB (mini) cable with your Garmin Sat Nav, because
1) with a USB (mini) cable, you CAN recharge your Garmin Sat Nav with your PC/Mac, which is not clearly mentioned in the user's manual. Remember, your Sat Nav doesn't come with a USB cable or an AC adapter (you need to buy them separately!), so you can't recharge the battery until you connect it with the vehicle power cable which does come with the Sat Nav.
2) you can download the latest map, update the software, and configure the Sat Nav via Garmin's website. You'll need to do all this (and it's simple) if you want draw out the maximum performance from your Sat Nav!
3) If possible, get a good cable rather than a cheap one, because they're not the same.
*You might already have this cable at home, because the same cable is used for many electric devices, such as mobile phones (e.g. Motorola), digital cameras and external HDDs.
Hope this helps!