Pay close attention, they are free click the area you want it will open a new window highlighted in blue click on it and save, you will need a program to decompress these files, I use WinRAR anyway after you open them just keep the .DEM file, and here is a site for one more thing you need
gusgs1_2.img, scroll down to USGS Land USC/Land Cover Scheme,download, it will read like this gusgs1_2.img.gz, before installing it in the mapmaker folder rename by removing the .gz