Magellan Roadmate 300?

I just bought this thig and I am aggravated. It came with a West region SD card which was blank! I get no detailed maps. How do I upload maps to this dumb this. I bought 2 other programs to try to fix the issue. Roadmate Manager from magellan wont download of course. I bought the Magellan MapSend Direct Route software and stil nothing. So now I have the Delorme Street Atlas 2007 USA and still nothing. the files are not readable on the GPS. Can anyone help?Magellan Roadmate 300?
If you can avoid it, never buy a GPS that requires separate maps. They are always a headache. This may seem to be a waste to you, but your best bet is to buy a Magellan roadmate 760 or later. This higher end model has a hard rive with all of the states and Canada preloaded, and some even have Europe. I have the 700 and 760, and trust me, its more convenient to just pack it in a bag and use it wherever i go, and i never have to think, oh, well, I'm going to Las Vegas lets say, i need to get the other SD card for the southwest, and after that, the Northeast or w/e to go to new york etc. Its like there catch phrase goes, because its true, with the Magellan 760 its "Turn it on and Go"