Installing PHP

Got some questions too ..

apt-get update
apt-cache search php5 shows 'php5' matching modules.

TeraVault:/etc/frontview/apache# apt-cache search php5
libapache2-mod-php5 - server-side, HTML-embedded scripting language (apache 2 module)
php5 - server-side, HTML-embedded scripting language (meta-package)
php5-cgi - server-side, HTML-embedded scripting language (CGI binary)
php5-cli - command-line interpreter for the php5 scripting language
php5-common - Common files for packages built from the php5 source
php5-curl - CURL module for php5
php5-dev - Files for PHP5 module development
php5-gd - GD module for php5
php5-imap - IMAP module for php5
php5-ldap - LDAP module for php5
php5-mcrypt - MCrypt module for php5
php5-mhash - MHASH module for php5
php5-mysql - MySQL module for php5
php5-odbc - ODBC module for php5
php5-recode - recode module for php5
php5-snmp - SNMP module for php5
php5-sqlite - SQLite module for php5
php5-xmlrpc - XML-RPC module for php5

After installing some of them (using apt-get install) , I now have :

TeraVault:/etc/frontview/apache# dpkg -l | grep php
ii  php5           5.2.0-8+etch9~ server-side, HTML-embedded scripting languag
ii  php5-cgi       5.2.0-8+etch9~ server-side, HTML-embedded scripting languag
ii  php5-cli       5.2.0-8+etch9~ command-line interpreter for the php5 script
ii  php5-common    5.2.0-8+etch9~ Common files for packages built from the php
ii  php5-curl      5.2.0-8+etch9~ CURL module for php5
ii  php5-gd        5.2.0-8+etch9~ GD module for php5
ii  php5-mysql     5.2.0-8+etch9~ MySQL module for php5

But still, I can't run PHP5 with Apache2.

apt-get install libapache2-mod-php5 returns an error. Means I can't run PHP as an Apache2 module. Or maybe I'm missing something (knowing I'm quite a noob - frenchy-noob speaking loosy english :) - ?

TeraVault:/etc/frontview/apache# apt-get install libapache2-mod-php5
Reading Package Lists... Done
Building Dependency Tree... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  libapache2-mod-php5: Depends: apache2-common but it is not going to be installed
E: Broken packages

Any clue on how to run PHP5 as CGI binary ? Or to install the PHP5 Apache2 module ?

And, where to find the Apache2 modules files (as a2enmod is not working to enable new modules .. ) ?

Lot of questions, and maybe some are typical noob questions .. but any help will be really appreciated.

Thx again for all your work guys ..

Cheers.