So you want copy-paste instructions to install GLPK on your Macbook? Here are the steps:

1. Download the latest version of GLPK from http://www.gnu.org/software/glpk/#downloading
2. Optional: Follow the instructions to verify the download (you might need to get GNU Privacy Guard or gpg for this. You can get it at http://gnupg.org)
3. Say it’s downloaded to your “Downloads” directory, go there and execute the following commands (using the terminal)

   cd ~/Downloads
   tar -xzf glpk-4.43.tar.gz
   ./configure --prefix=/usr/local # see note [1]
   make
   sudo make install
       

4. At this point, you should have GLPK installed. Verify it:

   which glpsol
   /usr/local/bin/glpsol
       

5. … and try help:

   glpsol --help
       

Now that you are all set-up, read up this excellent introduction using GLPK: http://www.ibm.com/developerworks/linux/library/l-glpk1

Notes:
[1]: HiveLogic article on why using /usr/local is better
[2] If you want MySQL support (or something “extra”) check out the INSTALL file in the package