I am new to Linux so I do not have any special preferences.
Yes I have a root access and the VPS is un managed.
I am newbie to the Linux world.
I will have a new website or maybe 3.
I've found that un managed costs vary a lot, as I've found various ways for settings ... some using Xen, others using OpenVZ, and other using Virtuozzo and I found that it all vary regarding Ram allocations for each VPS.
Also afraid to stuck with some over sell VPS as I had it before with shared hosting.
For un managed hosting VPS will it be easy to secure the server from being hacked? or it is an impossible job for a newbie guy like me?
Also for later on regarding updates or patching ... will it be good as well or not?
Finally I've found most people using Ubuntu server LTS, so do you advise of using it or any other distribution?
I've read a lot of reviews that most are advising for using CentOS or Debian, but I've found the majority are already using Ubuntu server.
Thanks and too much appreciated your time reading and value your inputs.

Note:
After a lot of reading I've found that the steps should be as follow: (the funny thing that I've read and know what I should do but each time I am trying to run a command using PUTTY I get an error)
- change root password to a secure one.
- create another user with admin access with a strong password as well.
- disable root remotely access.
- use secure connection to the VPS by using PUTTY key instead of username and password login .
- change the port to a high one with unusual figure like 26127 or any else
- disable ftp and use another secure one.
- install a fire wall, CSF firewall and Mod_security or anything else equal or more.
- keep the whole thing up-to-date.
- secure the whole VPS as much as possible.
- finally use a trusted script on the website and his why I will use Drupal (mostly the core ones and nothing else without any modules).

This is what I've got so far from reading many tutorials and still get a lot of errors when I follow them (howtoforge.com) is one of the famous websites I've visited.

Sorry for being long ... But I am really hope if you here be able to help or guide me.

- Late Edit -
I've forget to mention that some steps I've forget to mention are:
- using back ed control panel (like ISP config, VirtualMin) is facilitating the task but make VPS less secure, so using the command .