This is a collection of information that I have found usefull as I have been exploring various linux distributions.
Linux is a popular, freely distributable operating system, and here is a good place to start if you want to know more about linux and which linux distribution you should try and/or install.
Faced with a choice of over 300 linux distributions to choose from the first question most people ask is: which is the best linux distribution?
I am going to answer that by categorizing distributions that provide desktop solutions into 5 types of increasing complexity.
1. Ready to go 'out of the box'. An example of this is Mepis which is a full distribution and live CD in one package, comes pre-configured with NVIDIA, Flash, Java, multimedia codecs and other non-free applications, excellent hardware auto-detection.
2. A distribution that provides you with a desktop containing free GPL software, excellent hardware auto-detection, but you will need to use the package manager to install addition free & non-free applications. A good example of this type of distribution is Ubuntu and it's siblings Kubuntu, Xubuntu, which are basically ubuntu but with different desktop environments.
3. A binary distribution that installs the linux kernel and provides you with a base system. You however have to configure and install with the help of the package manager your desired desktop system and it's applications. Arch Linux would be a good example of this type of distribution. Arch Linux also has the Arch Build System, which also gives you the flexibility to compile packages from source, useful if there are additional options that you want that are not compiled in by default.
4. A source based distribution that installs the linux kernel and provides you with a base system. You however have to configure, compile, and install, with the help of the package manager, your desired desktop system and it's applications. Sourcemage would be a good example of this type of distribution.
5. A source based distribution that you have to build from scratch. Gentoo is probable the most well known example.
The linux distribution list gives you a bit more detail.