From nookDevs

Part of the NookColor portal

First, download an ext4 compatible bootable SD recovery from [http://forum.xda-developers.com/showpost.php?p=11447175&postcount=1]. You'll need about 120MB of space on the SD card for the CM7.1 and gapps ZIP files. Don't forget to verify that the MD5 checksums of the files you downloaded match the checksums in the XDA post.

Unpack the archive:

tar xvzf XXX_clockwork-0.1-ext4.tar.gz

This will create a raw image file in the current directory named 'XXX_clockwork-0.1-ext4.img', where 'XXX' is the size of the SD card image you chose to download. Follow the instructions in step 3 at [https://nookdevs.com/NookColor_Rooting#Steps] to burn this image file to an SD card.

The CWM image may have a boot partition that is too small for CM7.1 + latest Google Apps. You can format, install CM7.1, shutdown, copy gapps to the card, boot and install gapps WITHOUT reformatting the partitions, or create an image with a larger partition. The Nook Color can handle a vfat32 partition of no more than 1023 cylinders, 255 heads and 63 sectors. It needs to be marked bootable and aligned on cylinder boundaries. The volume label does not matter. This is the ONLY partition on the card that the original B&N firmware will see.

Next, download a 'flashable' ZIP archive of CyanogenMod. The best source for these is [http://download.cyanogenmod.com/?device=encore], directly from the cyanogen(mod) mirror network. 'encore' is the internal code name used by Barnes & Noble for the NOOKcolor, and any image built for the 'encore' should run. You may instead choose the latest nightly build to get all the fixes and latest features. You'll also want to download Google apps (gapps) from [http://wiki.cyanogenmod.com/wiki/Latest_Version/Google_Apps]. Be sure to verify the MD5 checksums of the files you download!

Both of these ZIP files need to be *copied* to the SD card you burned earlier. Do not use imaging software to do this, just mount the SD card normally and copy the files over into the first partition. After this is complete, safely eject the SD card and put it into your NOOKcolor. Reboot, and the NOOKcolor should display the CWR menu, version 3.0.0.6. Volume buttons move up and down, Home (N) selects/confirms, Power goes back. You'll need to do several things from the menu to install CM:

• Under 'mounts and storage', format system, data, and cache, do NOT format boot!
• Under 'install zip from sdcard', 'choose zip from sdcard', apply both ZIP files you downloaded earlier

When the last ZIP is done installing, remove the SD card and reboot. Your NOOKcolor should now be running CyanogenMod!