how to download this?

Please tell do you want install the package or do you want really download...?

http://packages.ubuntu.com/

To install on your system you don't need to download first...

Synaptic>repositories>under update tab check first two and refresh.Now you should be able to download that package by typing in terminal

sudo apt-get install ubuntu-restricted-extras

Ok so what i want is to install it. As i click on that link it says that i need to chose an application to with opened with. That gets me stumped, i have no idea what to chose.

To install please use the software-center from Application→Software center menu...

Seems you are new to Ubuntu so please be sure to read:

the Ubuntu Manual, it's very informative: http://ubuntu-manual.org/
Click on the "download Button" to download the latest PDF version.

http://ubuntuguide.org/wiki/Ubuntu:Natty

The Ubuntu 11.04 Unity interface
http://theravingrick.blogspot.com/2011/04/my-effort-at-writing-help-for-unity.html
The Unity interface: http://www.omgubuntu.co.uk/natty/#what

- https://help.ubuntu.com/community/SwitchingToUbuntu/FromWindows
- The Ubuntu pocket guide: http://www.ubuntupocketguide.com/
- The online help https://help.ubuntu.com/10.10/index.html

Ubuntu web sites:
http://yaserxp.wordpress.com/2008/05/29/discover-the-best-ubuntu-resources-on-the-web/

Ubuntu online magazine: Full Circle Magazine - Ubuntu's 'unofficial' magazine.
http://fullcirclemagazine.org