I need to install Wordpress on an Ubuntu 14.04 Server. From what I've googled, I can install it via apt-get install or download the package from wordpress.org.
What option should I use for better administration? Specially when updating the Wordpress package.
Also, how to update downloaded packages? (installations that did not use apt-get)
PS. We plan to run more than 1 wordpress site here. (I don't know if this matters in the setup)
I would install using the wordpress.org package. Wordpress keeps itself up to date, so staying up to date using apt wouldn't be useful and could potentially conflict. However setting up Nginx, MySQL, etc using apt-get is a good choice.
Even better, use EasyEngine. It automates a lot of things including setting up a caching layer.
Put another way, what is version control? - you can use Ubuntu's package manager to download wordpress of course, it will be harder to roll back using apt-get and you may have to install packages outside of Ubuntu's repositories anyway (for contributed modules, which in turn have their own dependencies). I recommend that you investigate version control methods such as SVN or GIT etc., as this makes it easier to patch manage the application and to roll back changes, use experimental features and clone sites from dev to production or vice versa. the Ubuntu package repository install ensure 'Long Term Support' and that things have been tested but obviously you only get the package and it's minor and major updates - sometimes there will be a new version but it won't be available in your repository as it hasn't been tested with you Ubuntu.