[Nook Color Q&A, Help & Troubleshooting] GMPOWER:
You can sideload to the stock firmware. The steps that you take all depend on what you plan on ultimately doing with the device.

If you plan on only occasionally installing an app, you can make a bootable recovery image, and use an update script to install the apps for you. You will have to install a launcher app, or the attached Nook Color App Manager app, so that you can access the apps that you install. The Nook Color App Manager app will allow you to access the installed apps from the factory app list.

Download the attached manualsideloader-1.06.10.basic.zip file.

Also download the attached nook.color.app.manager.apk if you want to use the stock app launcher to launch you installed apps.

Open the manualsideloader-1.06.10.basic.zip file, and place whatever_app.apk file into the /data/app folder

Download the bootable ClockWorkMod version 3.2.0.1 file: http://tinyw.in/0Vw -If using windows, use Win32DiskImager to flash this image to your SD card. Make sure that flash you flash the file to your SD card using a card reader, not while the card is inserted into your device.https://launchpad.net/win32-image-writer/+download

Place the modified manualsideloader-1.06.10.basic.zip file onto the SD card that you just made.

Turn off your Nook Color (If it is turned on).

Insert the bootable SD card into your Nook Color

Turn on your Nook Color

When ClockWorkMod boots Select:

install zip from sdcard

choose zip from sdcard

select manualsideloader-1.06.10.basic.zip

confirm that you really want to run the update

Wait patiently and follow onscreen directions

remove bootable CWM SD card from the Nook Color and select reboot

The apps should now be installed on your device

If you plan on installing apps often, then you can use a bootable recovery image, and an update script to enable ADB. You can then just hook the NC to the computer and adb install whatever.apk that you want. You will have to install a launcher app, or the attached Nook Color App Manager app, so that you can access the apps that you install. The Nook Color App Manager app will allow you to access the installed apps from the factory app list.

Download the attached manualsideloader-1.06.10.adb.zip.

Also download the attached nook.color.app.manager.apk if you want to use the stock app launcher to launch you installed apps.

Open the manualsideloader-1.06.10.basic.zip file, and place whatever_app.apk file into the /data/app folder

Download the bootable ClockWorkMod version 3.2.0.1 file: http://tinyw.in/0Vw -If using windows, use Win32DiskImager to flash this image to your SD card. Make sure that flash you flash the file to your SD card using a card reader, not while the card is inserted into your device.

https://launchpad.net/win32-image-writer/+download

Place the modified manualsideloader-1.06.10.adb.zip file onto the SD card that you just made.

Turn off your Nook Color (If it is turned on).

Insert the bootable SD card into your Nook Color

Turn on your Nook Color

When ClockWorkMod boots Select:

install zip from sdcard

choose zip from sdcard

select manualsideloader-1.06.10.adb.zip

confirm that you really want to run the update

Wait patiently and follow onscreen directions

remove bootable CWM SD card from the Nook Color and select reboot

The apps should now be installed on your device, and you can now install future apps by hooking your device to your computer and adb install whatever.apk non system app you want in the future.

For anything beyond these basic functions, you will need to root the device. http://xdaforums.com/showthread.php?t=1494901