Modem installation

[John French]

I regret to admit that I am still floundering about trying to install 
either of my two Winmodems. I got through "make" with the help of some 
kind forum contributors. Now I am stuck on "make install" !

1. Lucent modem asks :

    Where is the linux build directory that matches your running kernel ?
    [/usr/etc/linux]

2. Smart Link modem says :

    Review and edit 'Makefile' (if needed):

    In many cases you will need to correct path to your local kernel
    source tree:

         KERNEL_DIR=/path/to/linux

    Default KERNEL_DIR is '/lib/modules/<kernel-version>/build'. Many
    Linux Distributions use directory '/usr/src/<linux-<version>' also.

My attempts to find successful answers to either of these questions have 
all failed. Advice greatly appreciated.

Is there a good reference source for handling problems like these, so 
that we newbies don't have to bother you so often ?

John