Your Guide is good but there are some errors and assumptions made in it.

So if i may edit it, this is how it would follow:

Installing Nitdroid N12 UMay manually *Easy/Super Newb Friendly*
This guide assumes that eMMC is not partitioned
This guide assumes that you will be using nitdroid-kernel-2.6.28-06_final1_armel.deb
This guide assumes that you have extras, extras testing and extras devel repos added and updated.
This guide assumes that you have no mmc card inserted
This guide also assumes that you have some form of root access (rootsh,sudser, etc)

1.Download N12-UMay and the kernel and copy them onto the eMMC (internal memory).
N12:http://downloads.nitdroid.com/e-yes/N12_UMay.tar.bz2
Kernel:http://downloads.nitdroid.com/e-yes/...nal1_armel.deb

2. To make it easier, rename 'N12_UMay.tar.bz2' to 'n12.tar.bz2' and 'nitdroid-kernel-2.6.28-06_final1_armel.deb' to 'nitdroid.deb'
And then disconnect N900 from computer.

3.Install all the repos on to HAM (Application Manager)
http://www.nokiadistrict.com/reposit...or-nokia-n900/
This is the easiest method of enabling repos on the n900, browse the site on your phone, and press each of the Click here links to auto install the repo.

4.Open HAM (application manager) and then go to Download ->All-> then search root and choose rootsh -> install it -> close HAM

5.Open Terminal and write as follows
sudo gainroot
apt-get -f update
apt-get install leafpad bzip2 multiboot-kernel-maemo
cd ..
mkdir /and
mount /home /and *NOTE* its is 'mount<space>/home<space>/and' Some people get it wrong.
cd /and
bzip2 -d /home/user/MyDocs/n12.tar.bz2
tar xvf /home/user/MyDocs/n12.tar
dpkg -i /home/user/MyDocs/nitdroid.deb
leafpad /etc/multiboot.d/11-NITDroid-mmcblk0p2-2.6.28.NIT.06.item

6. When leafpad opens, change
ITEM_DEVICE=${INT_CARD}p2
to
ITEM_DEVICE=mmcblk0p2
*important* Then SAVE before closing, people who complain about the guru meditation error often forget to save before closing =="

7. Reboot with keyboard out and choose option 2 (nitdroid)
8. Wait for it to boot
9. Enjoy