I know that wannabe hackers think they need Kali Linux but it’s a bad plan. Choosing the best Linux distribution is dependent on purpose, and as a beginner your purpose is “general”. Beginners should use an easy, general purpose OS and step to Kali when they know a little bit. Kali tools can be used on other distros anyway, and if they want to be half-decent hackers they’ll appreciate the experience with day-to-day OSs and tools – the stuff normal people use.
Ubuntu & Mint
For beginners I recommend Ubuntu or Mint, which are Debian based anyway (like Kali). Mint also has a really nice GUI and it’s extremely user friendly. I use Kali for pen testing work and Mint for a general desktop. The newest release of Mint has got some seriously high praise so it’s worth checking out, plus you can be reassured that far more intelligent people than either of us are working to keep it secure.
Linux distributions I have used are below, with some basic suggestions for how to use them. Most are Debian based. There are a million sites online that compare Linux distros so for any of the others I suggest Google. Or check out Distrowatch or Wikipedia’s Linux comparison page.
Based on Debian but has its own software repositories, Ubuntu is user friendly and has a huge amount of online support and documentation. This is a great choice for beginners and frequent releases with LTS (long term support) come out every couple of years. Ubuntu desktop has a nice GUI, massive software repositories so lots of available programs, and is probably the most widely documented distro online. Also has a lightweight, powerful server version which is excellent for system administration.
Widely used desktop version, well supported and really user friendly, the newest version of Mint (Cinnamon), has achieved pretty widespread acclaim. This is definitely the way into Linux for beginners, and it has decent security with a wide network of support.
Kali is a highly specialised set of tools for security and pen testing. For first time/beginner Linux users is a bad idea. It’s not secure unless you really know how to configure it, and will only provide inadequate/poor protection as a result. I don’t mean that people shouldn’t try it, I just think that it’s bit like giving a Honda Fireblade to a learner driver. Despite all that warning it is (much like a Firebird) absolutely deadly once mastered.
Described by Anonymous as “the closest to online anonymity you can get”, Tails is a Debian-based distro that is directly focused on anonymity and security online. It leaves no digital footprint and is supported by Tor so that’s the general tone that we’re working here. You can use it as a Live USB/DVD or as a regular install (on a VM for example). If you are interested in security then an install of Tails is a no-brainer.
CentOS / Red Hat Enterpise Linux
I’m a big fan of RHEL for business and larger server architectures. It’s not free (Red Hat is trademarked and redistribution is not allowed) but it is tested, stable and comes with excellent support. For pro solutions it’s very helpful to replace Google+documentation with actual support technicians. CentOS and RHEL are officially in collaboration, with CentOS being the official, free alternative to RHEL. This is a great choice if your business/client uses RHEL, because you can then work on it and pick up tricks without paying anything.