crosstools for morons

OK, I must be a moron....

I migrated my system to a new machine.  New install of debian, new
install of Don Kegel's crosstools, AFAICT everything is set up right.

I have GCC_INCLUDE_DIR set to /home/arm/usr/include.  that directory is
populated with all of the arm include files....

But none of the linux-arm-* programs see *any* include files.  They
can'f find stdio.h....

I had this running flawlessly on the old system....  And I have
convinced myself that my setup is the same.  So I am missing something
very basic.

FWIW, I am using a slightly modified setup described here:
http://www.comp.leeds.ac.uk/jj/linux/arm-sbc.html

Is there a HOWTO somewhere for cross-compiling kernels, for example?  A
step-by-step recipe, since I am obviously going slowly senile.....