The debian kernel-image-2.6.0-test2 didn't even boot on my machine. I have compile kernels before, with now and then a succes story. I encountered the following problems with 'deploying' kernel 2.6.0-test4:
- blank console (solved)
- aRtsd (KDE soundserver) will only use OSS-emulation API of ALSA (solved)
- network card won't work (solved)
- mousewheel (Logitech mouse) won't work in X (solved)

I downloaded the Linus-kernel, applied no patches. Used "make menuconfig" to configure the kernel. At first I was a bit overwhelmed by all the (already expanded) options. I did a "make defconfig" to get a quite minimal configuration to start editing on.

Some tips:
- use make defconfig to get an tiny default configuration without all/most options expanded.
- compile all framebuffer support (for graphics on consoles) you need into the kernel else you might end up with a blank screen like I did.
- apt-get install module-init-tools, to get a 2.4/2.5/2.6 compatible init. Testing and unstable have a newer version.
- compile ALSA as module, this might improve compatibility with older apps.
- apt-get remove knx-alsa ; apt-get install alsa-utils/testing alsa-base/testing alsaconf/testing, to get a 2.6 compatible ALSA-lib/utils.

Usefull docs:
"The post halloween doc" (list of known problems+solutions with late 2.5 kernels)
HowTo Upgrade To The 2.6 Kernel (decolapsing all comments can be helpfull)

Building:
Code:
make mrproper 
make menuconfig or make xconfig 
make 
make modules_install 
make install
Modify your lilo.conf

How I fixed the problems I encountered:

- Though I did compile the framebuffer as module, it didn't solve the blank console by compiling it into the kernel. Also enableing the nVidia Riva/GeForce support didn't help me either (i have a Geforce4 MX440). So after some fiddeling I disabled "VGA 16-color graphics support" and enabled "VESA VGA graphics support" in the "Graphics support" menu. If I enable 16-color VGA my console remains blank.

- Upgrade ALSA to fix the wierdness with aRtsd
I first tried to solve it by compiling ALSA als module, I read somewhere that ALSA is new in the kernel and that some apps still require ALSA modules like in the ol' 2.4.x days.
Code:
apt-get remove knx-alsa
apt-get install alsa-utils/testing alsa-base/testing alsaconf/testing
alsa-utils from unstable requires a new libc6 (>= 2.3.2-1), didn't want to upgrade...

One of the ALSa packages will ask what drivers to load, select the card(s) you have configured for your kernel.

- boot with "acpi=off" to get my sis900 networkcard working, or compile the kernel without any powermanagement. This seems like a gross bug to me.

- Apparently the autodetect of the "mouse-protocol" in X is broken for kernel 2.6, set the used mouse protocol from "PS/2" to "IMPS/2". Snippet:
Code:
Section "ServerLayout"
	...
	InputDevice    "PS/2 Mouse" "CorePointer"
EndSection
...
Section "InputDevice"
	Identifier  "PS/2 Mouse" # Match this with InputDevice above
	Driver      "mouse"
	Option      "Protocol" "IMPS/2" # Change this
	Option      "ZAxisMapping"     "4 5"
	Option      "Device" "/dev/psaux"
	Option      "Emulate3Buttons"  "true"
	Option      "Emulate3Timeout"  "70"
	Option      "SendCoreEvents"   "true"
EndSection