Suitable Driver ?

HI       I have to setup PERL to interact with PGSQL.       I have taken the following steps.
       1.Installation of perl_5.6.0 under Redhat Linux 7.0       2.Installation of POSTGRESQL under Redhat Linux7.0
       Both are working perfectly as seperate modules.
       Now I need to interface perl with PGSQL.
       I need to what's the best possible soln.
       I have installed latest DBI from www.cpan.org
       Now i need to install DBD For PGSQL .Is       this the driver i have to work on for pgsql ?.       Or do I have
anyother option to connect to pgsql       from perl . Indeed i've found out an other way       to use Pg driver
providedby PGSQL to interface       perl with pgsql.
 
       I need to exactly know the difference between       use Pg ; and use DBI ; Need to which one is       proceeding
towardscorrect direction under what circumstances.
 

       when I tried to install DBD-Pg-0.93.tar.gz under Linux       i get
       Configuring Pg       Remember to actually read the README file !       please set environment variables
POSTGRES_INCLUDEand POSTGRES_LIB !
 
       I need to know what these varibles POSTGRES_INCLUDE and POSTGRES_LIB       should point to ...
       and when i tried to run perl test.pl, the program to test the
installation of the module which       comes with the tar.        I get the error
       OS: linux       install_driver(Pg) failed: Can't locate DBD/Pg.pm in @INC (@INC
contains: /usr/l       ib/perl5/5.6.0/i386-linux /usr/lib/perl5/5.6.0
/usr/lib/perl5/site_perl/5.6.0/i3       86-linux /usr/lib/perl5/site_perl/5.6.0 /usr/lib/perl5/site_perl .)
at (eval 1)       line 3.       Perhaps the DBD::Pg perl module hasn't been fully installed,       or perhaps the
capitalisationof 'Pg' isn't right.       Available drivers: ADO, ExampleP, Multiplex, Proxy.        at test.pl line 51
 
       Any body who can clarify is most welcome....
       with regards,       Prassanna...