1) There are three parts.
a) First is to enable adb on your Nook by going to Settings > Device Information > Developer Options.
Then checking 'Enable ADB'.
b) Putting 0X2080 (or something like that, check the developer guide) in the .android android usbini file.
c) INstalling drivers.
First - you should try the drivers that you got from the Nook site. NOT the ones from xda.
Second - you will have to try multiple times. It's very hit and miss.
What nookdev walkthrough are you talking about? If you have access to submit tickets, then submit a ticket. Ticket is best way to get help.