I think that it depends whether the support for that type of module was already compiled in.
I would start with "make oldconfig" before "make xconfig" in the above instructions. This will use your last .config options before you make changes. It also validates your .config file.
If you are adding a sata drive and your kernel was compiled without sata support,
i.e.:# CONFIG_BLK_DEV_IDE_SATA is not set
in .config, then you would need to recompile the kernel with this option changed.
On the other hand if this is a module for an ide drive, then for the 2.6 kernel, you might be able to just
make modules && make modules_install
The nvidia installer does something like this to compile and install the nvidia.ko kernel module.
So to use your network device example. You are adding a device that uses the apricot network device driver. If the .config file says "CONFIG_APRICOT=m" then either a new driver isn't needed or you need only to install the source-code and run "make modules && make modules_install"
Also, there are howtos and README documents in the kernel source. Be sure the read through them. The source code the you are installing will probably have documentation with the source that will give you detailed instructions. There are also instructions on how to install drivers with the source code.
When I just looked in my /usr/src directory, there was a sub-directory "kernel-modules" present. Two kernel module source directories were inside. Each module's Makefile had a "make all" target to compile the module and "make install" target to install the module. Each module also had a README and INSTALL file.
This is the first of two methods for recompiling a kernel module given in the /usr/src/linux/SuSE-README file:
The first method involves the following steps:
(1) Install kernel-source.$ARCH.rpm.
(2) Change to the /usr/src/linux directory. Configure the kernel
(for example, ``make oldconfig'' or ``make cloneconfig'', see
HOW TO CONFIGURE THE KERNEL SOURCES).
(3) Create files required for compiling external modules:
(4) Compile the module(s) by changing into the module source directory
and typing ``make -C /usr/src/linux M=$(pwd)''.
(5) Install the module(s) by typing
``make -C /usr/src/linux M=$(pwd) modules_install''.
If I hadn't read the README file in the kernel source, I would of missed the "make modules_prepare" step that my system requires.