I’m a Linux fanatic, been using it for years. I run my own servers, etc.
Ubuntu is a GREAT distribution to go with. I personally can’t stand any of the other “desktop” style distros, like Gentoo, Fedora or Suse.
How easy it will be to “learn” Linux depends on what you want to use it for. If you want a regular desktop for home use (email, surfing, chatting), just drop Ubuntu (which uses Gnome as a graphical interface) or Kubuntu (which uses KDE as its interface, which I prefer) on to some average hardware and you’re good to go.
If you’re hoping to be able to run any Windows app you want, you won’t want Linux, as getting them installed and running may or may not work. It gets pretty complicated, especially games.
If you’re wanting something to learn to increase computer skills and make yourself marketable in the IT industry, then I would recommend either Ubuntu, Red Hat, Suse, or Fedora, as those dists are used more often in corporate environments (of course, I still use good old Slackware no matter what company I work for).
So, I guess the question is: What are you looking to use it for?