The USB-1 that you mentioned is a cord and USB-SERIAL converter all rolled into one. Separate converters can be had very cheap but if you have no cable at all to start with the USB-1 would be a great way to get hooked up.
Probably the most frequent mistakes that are made are incorrect drivers or plugging the cable into your ocmputer before installing the software. Both are a must do for proper function. Get the right drivers and install them before plugging in the USB-1.