One way to distinguish between distros is package management. Debian, Ubuntu, Mint and other Debian derivates use apt/deb. Fedora and other RH derivatives use rpm. Other distros use whatever they use.

If you don't care one way about package management, then you might care about which versions of packages are supported by default. For example, this is Lubuntu's (essentially Ubuntu's).

http://distrowatch.com/table.php?distribution=lubuntu

You can check other distros' package versions there too, as well as package management, file systems, etc. Of course nothing says you can't install whatever version of whatever package on whatever distro that you want, but it's nice to know from where you'll be starting.

I also use Fedora. Mint is an Ubuntu derivative, so basically any tutorial about Ubuntu will also work for Mint, which I think is a big plus.

There is LMDE too: Linux Mint Debian Edition, which is based on Debian testing (so it's a rolling release).