As I faced some problems when re-installing Debian on my AmigaOne I've decided to post my experiences here so that other users may benefit from it and avoid making the same mistakes that I have done:
Follow EXACTLY the steps described in your manual, this is very IMPORTANT!
If you recieve strange error messages or even kernel panic messages during installation, you have to turn off DMA for your harddisc until an updated Version of U-Boot is released which fixes this. To turn DMA off you have two choices, either add a boot parameter when booting your system called ide=nodma or you may also install the package hdparm to disable DMA. This is done in the following ways (one harddisc as Master on first controller assumed):
apt-get install hdparm
hdparm -d 0 /dev/hda
The first call installs the hdparm package and the second call disables (-d 0) DMA transfers for harddisc device /dev/hda. The hdparm method is the prefered way of disabling DMA, as it allows the kernel at least to boot with enabled DMA. If, however, your system won't boot correctly you must use the kernel parameter setting, please refer to your system manual how to do that.
Update to the latest kernel (currently 2.4.22), available under:
Please follow the installation instructions carefully, updating the kernel is really no trivial task and may corrupt your harddisk if you doing it wrong!
If you plan to use always the latest software you have to use the unstable/testing branch of Debian. But be warned: Because of the testing nature it can happen that you will get some dependency errors when trying to install packages. If this happens, just wait one or two days until the package maintainer has updated the faulty package. And of course it can also happen that the whole system won't work anymore because of broken packages, faulty software etc. If you plan to use the Linux A1 for work always use the stable branch of debian. If you love adventures (like me :) then switch to unstable/testing.
You have to update XFree86 if you have a radeon based graphics card, else you will get the nice error message "no screens found" when trying to start the X system. The stable Debian installation will install XFree V4.1.0 but you need at least V4.3.0 to have full radeon support! Please follow your manual instructions exactly to upgrade XFree86, failure to do so will result in a non-working X environment!
Be careful when updating KDE to V3.1.x! Again the stable branch is much older then the testing/unstable branch. If you want to use always the latest packages you are stuck to use the testing/unstable branch. For all others who do not require the latest KDE programs, enter this to your sources.list file to get the latest kde version:
deb http://download.kde.org/stable/3.1.3/Debian stable main
These are the most important problems I faced during my install-sessions :)
Finally I would like to inform you about the program synaptic, a very nice Debian Package Installer with a very good X GUI, it allows you to easily add all missing packages to your system. (apt-get install synaptic)