DVD - media not recognised and not playing- cds work

New to Ubuntu: read the Ubuntu Manual, it's very informative: http://ubuntu-manual.org/
Click on the "download Button" to download the latest PDF version.
The online help https://help.ubuntu.com/10.04/index.html

Relax and fun:
http://planet.ubuntu.com/ and Full Circle Magazine http://fullcirclemagazine.org/

Please read the already answered questions: https://answers.launchpad.net/ubuntu/+source/totem

Play mp3 and dvd and other stuffs under Ubuntu using Medibuntu

First please install https://help.ubuntu.com/community/RestrictedFormats

You need to have extra repositories enabled..

Please first enable the universe and multiverse repository:

Open System → Administration → Software sources → [ Tab Ubuntu software ]

enable "Community-maintained Open Source software ( universe )"
enable "Proprietary drivers for devices ( restricted )"
enable "Software restrictecd by copyright or legal issue ( multiverse )"

Close and confirm the repository reload.

Then open a Terminal from the menu Applications→Accessories→Terminal

Tip: right click with mouse on the terminal title caption and select the item "Always on Top" doing this you will force the terminal window to stay on top of the other windows and you will find very easy to copy single row from this web page into the terminal...
Something more about using the terminal https://help.ubuntu.com/community/UsingTheTerminal

Then type or better copy and paste a row a time then press enter:
(Tip: select the single row to copy then right click into the terminal and to quick paste click with middle button of mouse )

and type or better copy and paste:

sudo aptitude install vlc smplayer mplayer

To get better dvd playback and optional packages here the medibuntu available software list http://packages.medibuntu.org/
you need to add the medibuntu http://www.medibuntu.org/ repository to your /etc/apt/sources.list file:
( here the medibuntu howto https://help.ubuntu.com/community/Medibuntu but see below )

In short please open a Terminal from the menu Applications → Accessories → Terminal and type or copy and paste:

sudo wget http://www.medibuntu.org/sources.list.d/`lsb_release -cs`.list --output-document=/etc/apt/sources.list.d/medibuntu.list; sudo apt-get -q update; sudo apt-get --yes -q --allow-unauthenticated install medibuntu-keyring; sudo apt-get -q update

-- give your user password when requested, you don't see nothing when you type it, then press enter

Now to install, type:

sudo apt-get update
sudo apt-get install ubuntu-restricted-extras libxine1-ffmpeg
sudo aptitude install libdvdread4 libdvdnav4 regionset gnome-mplayer
sudo aptitude install non-free-codecs
sudo aptitude install gstreamer0.10-pitfdll gstreamer0.10-plugins-good
sudo aptitude install gstreamer0.10-plugins-ugly gstreamer0.10-plugins-ugly-multiverse
sudo /usr/share/doc/libdvdread4/install-css.sh

give your user password when requested, you don't see nothing when you type it, then press enter.

You can also install other Medibuntu repository provided optional software http://packages.medibuntu.org/ :

Also optionally you can also install googleearth ans skype:
sudo apt-get install googleearth
sudo apt-get install acroread

Hope this helps

Thanks for the advice. I've read the Ubuntu PDF and installed the required codecs, I have followed all of the other advice to the letter, and I have tried quite a few media players. None of them recognise the DVD. When I load a a DVD there is some DVD activity then it stops: The error message in Gnome MPlayer is a typical response:
Couldn't open DVD device: to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
libdvdread: Using libdvdcss version 1.2.10 for DVD access
libdvdread: Could not open /dev/dvd with libdvdcss.
libdvdread: Can't open /dev/dvd for reading
Couldn't open DVD device: /dev/dvd (No medium found)
No stream found to handle url dvd://

In Ubuntu system/admin/disk utility - there is no medium detected and the eject button will not work - but it does in VLC!

After following the advice from Marcobra again I adjusted the settings in CD/DVD creator - problem is solved
 - DVD is working fine.

Go to Applications/Accessories/ CD/DVD creator/ Edit/ Preferences /Media/

Here it is possible to change the media handling settings and you can select your preferred media player to open on DVD insertion.

Thanks for your help.