I am now presuming that you have downloaded the latest
versions of ax25-apps, ax25-tools and libax25.
Lets say for easyness sake that you placed them into /home/ax25/progs
The files would be;
libax25-0.0.9.tar.gz
ax25-apps-0.0.6.tar.gz
ax25-tools-0.0.8.tar.gz
node.0.3.0.tar.gz
All my examples from here on will be addressed to that directory.
Now you can commence and install the apps tools and lib's.
The following are exacht commands, please read carefully as one syntax
error means nothing will work for you.

You need to be root to install all the stuff, (not to compile it tho)
however there is no harm in doing it all as root, remember one thing,
root is evil, root can do what he wants which means destroy the whole
system in one command, so be carefull and only use root when it is
nessasary to do so.
A small note, read the INSTALL and README files FIRST, they are there
for a reason, that is TO HELP YOU, if you have read those files then
you will understand most of the commands below.

cd /usr/local/src
tar xvzf /home/ax25/libax25-0.0.9.tar.gz
cd libax25-0.0.9
./configure --exec_prefix=/usr --sysconfdir=/etc --localstatedir=/var
make
make install
cd ..
Thats the lib's installed, now we can install the apps and tools.
tar xvzf /home/ax25/ax25-apps-0.0.6.tar.gz
cd ax25-apps-0.0.6
./configure --exec_prefix=/usr --sysconfdir=/etc --localstatedir=/var
make
make install
# Another note;
# If you already installed and configured your *.conf files then
# be advised that using make installconf will OVERWRITE exsisting
# files.
make installconf
cd ..
tar xvzf /home/ax25/ax25-tools-0.0.8.tar.gz
cd ax25-tools-0.0.8
./configure --exec_prefix=/usr --sysconfdir=/etc --localstatedir=/var
make
make install
cd ..
tar xvzf /home/ax25/node-0.3.0.tar.gz
cd node-0.3.0
./configure
# Hit enter 3 times to accept the defaults presented on the screen.
make
make install

THATS it, things are now installed.