Programming for PostgreSQL

I am new to database development and programming and administration. I am
using PostgreSQL 7.1.3.

I am trying to run a simple program to insert data into a database.

I am having a problem compiling the program. I am following directions from
Bruce Momjian's book called "PostgreSQL Introduction and Concepts"

it instructs me to complie for C++ using the following format:
g++ -I/usr/local/pgsql/include -o myapp
myapp.cpp -L/usr/local/pgsql/lib -lpq++

when i run this i get the following error:
/usr/bin/ld: warning: libpq.so.2, needed by /usr/local/pgsql/lib/libpq++.so,
not found (try using --rpath)

i know the file is there, i have visually seen the file.

also, what is --rpath?

thank you
Liam