Don't be too worried about the lack of manual. AFAIK, most if not all PDAs don't come with manuals on hardcopy anyways. It's usually included on the installation disc for the desktop software or another CD.
Speaking of which you'll also want the desktop component software for your PC. It's called Palm Desktop. Not required to use your handheld, but HIGHLY recommended, as it let's you transfer programs and media files you download from the intnernet onto your PC and then transfer onto your handheld. U can also backup your PIM data onto your PC and enter data from there as well. Palm Desktop is free for Palm users. IIRC, it'll ask for your handheld's serial # prior to DL it on PalmOne's support site. Find the section for the m515
As for charging, some gadgets let u charge solely through USB. Others, no. Middle road is there is power trickling through, but not nearly enough, so it may take a while. If it ain't enough, consider going to places like www.pdaparts.com, www.pdaaccessories.net, and ebay for spare parts for the AC. Palm's site is also good, but they may not have spare parts for older handhelds, and may charge more if they do.