absolute beginner

I ahve red hat enterprise linux 3. This came with PostgreSQL already installed. An online book says that I should have
thefollowing directoreies under /pgsql : /bin, /data/, /data/base, /doc, /include, /lib, /man. However, I only have the
directories:/data, /internal, and /server. I have the makefile, Makefile.global there as well. 

I am hampered in my ability to follow the online tutorial pages if my configuration is different from everyone elses.

What should I do? Should I upgrade this 7.3.4 to 7.4? Or do something else?

Thanks

Lee