I know that guide is for Openelec, but the process will be the same for you. Download an image of Raspbmc and write it to the USB stick with the instructions in the link. Then use the guide on how to install to USB to make your SD card.
*I think thats how anyway haha, im still new too.
Ps, make sure you do a FULL format on your SD card before writing the image.
Oh ya I remember seeing that too, I just used the one for windows and it worked first try. I have had alot of problems writing images that I have downloaded and ZERO problems writing images that I have created on my own. I remember seeing a script to use to verify the images after download but can't think of it right now. Does anyone else know how to verify images downloaded?
its a link to the image not the program. the program is for windows only. you have to write the images yourself on mac through terminal (command prompt) and there are only steps on how to write it to an sd card.
the only time in the past 4 years I've wished I owned a windows computer lol
Ok then write it to an sd card as this is mandatory for the rpi anyway.
Then, if I recall correctly... during the install process using the sd card in the rpi the installer will ask you about installing to a usb drive - have it handy (but not plugged into the pi). I think you have 60 seconds from the prompt to plug in your usb drive and that should be it. Let the process complete and you should be good to go.