There shouldn't be any charges to transfer music from comp. to phone. Also, no copyright probs.
You're also going to need the Droid's Drivers so the computer will fully recognize it. Before I got the drivers, in Device Manager there was a driver for the "Motorola A855" missing. This is where you get it.
There are different ones for 32 bit Operating Systems and 64
If you download the Software Developers Kit (SDK) you can get the fully functionality out of this phone while plugged into your computer. The SDK will give you the option to download the USB drivers.