This is my top thing to do after installing OpenMandriva 2013:

1. Update your media/repository
To enable installing new software you must update and enabling the media/repository. You can do this by two way:
a. with OpenMandriva Control Center (Drakconf) -> Software Management -> Configure Media sources for install and update. Click Add button and wait for system to download all default source.

b. by Command with URPMI
Open Konsole/Terminal and login as root:

su
urpmi.addmedia --distrib --mirrorlist 'http://downloads.openmandriva.org/mirrors/openmandriva.2013.0.ARCH.list'
urpmi --auto-update

change the ARCH value with i586 or x86_64 that suites your gear.

2. Install Chromium Browser
To install Chromium Browser, just type this in terminal (as root):

urpmi chromium-browser

3. Install Flash Player
to install Flash Player, download first the Adobe Flash Player form Adobe website:

http://linuxdownload.adobe.com/adobe-release/adobe-release-ARCH-1.0-1.noarch.rpm

change the ARCH with i586 or x86_64 that suite your gear.

Install it with urpmi:

urpmi adobe-release-x86_64-1.0-1.noarch.rpm

4. Install dirty codecs
this is probably not suite with your opensource mind, but I’m usually do this:

urpmi gstreamer0.10-plugins-bad gstreamer0.10-rtmp gstreamer0.10-flac

5. Install Java

urpmi java-1.7.0-openjdk

this is openJDK spin, for official Oracle releases, please download from their site.

6. Install another window manager
probably you’re not one of KDE guys, but you still can use OpenMandriva with another WM. Install another WM with this command:

urpmi task-gnome or urpmi task-gnome-minimal
urpmi task-xfce or urpmi task-xfce-minimal
urpmi task-e17 or urpmi task-e17-minimal
urpmi task-lxde

7. Install another bittorrent client
you can choose the following client that available on OpenMandriva repo:

 urpmi transmission-qt4
 urpmi transmission-gtk (for gtk interfaces)
 

8. Installing another IM client
you can install another IM like Pidgin or Telepathy (beside Kopete) with URPMI:

urpmi pidgin
urpmi telepathy-kde-accounts-kcm​