Just wanted to update this thread with more explicit instructions on restoring the stock BN if you can't boot and can't activate either CWM recovery or BN recovery.
Here's how to restore BN recovery from SD card that will cover 99% of cases(*):
There is a rootpack (with instructions)
that can make a bootable SD with clockworkmod. Make one. (I know the page says that 1.0.0 and 1.1 aren't supported --that only applies if you are using the rootpack to root, it doesn't apply if you are just using it to repair recovery which will work on any Nook).
Then power off your Nook, put the SD in, and power it on and:
- From the Clockwork Recovery home screen use the volume buttons to navigate to “Install Package from SD Card” and press the home (“n” button) to select it.
- Select “Browse for Package”
- Navigate to optional/ then select RemoveClockwork.zip
- Select “Yes”, then wait for the process to complete.
- Power off, remove the SD card and use the 8-boot restore to rewrite the stock OS and the factory restore to wipe data if you need it completely clean.
If you have a valid clockworkmod nandroid backup and just want to repair a bad clockwork install and restore your last working nandroid backup, instead of RemoveClockwork.zip in the above, choose InstallClockwork.zip.
* What's the 1% that this won't work for? When you've damaged the initial partitions. Then you do need a repartition boot that Volwrath gave links to.