Disclaimer: This is not an ad – I don’t own stock in Linode and I’m not getting a discount.
I wanted to have my own full-featured VM (Virtual Machine) to muck around with. After a misstep or two, I decided to try Linode (short for Linux Node) and I’m very happy with it. You have your very own Linux machine to play with, in fact you can pick from a large selection of Linux distributions. The documentation is great and so is the technical support. I can use this as a portable Python machine for work (since I can use it from the Reference Desk via PuTTY), for learning, and also for personal stuff like mucking about in Drupal. At $19.95 a month for the basic setup, Linode is a pretty good deal.
If you have ambitions of becoming a Systems Librarian some day, you really ought to be familiar with Linux, UNIX or similar systems. Part of being a Systems Librarian is being a SysAdmin, and the Systems tend to be of the UNIX-flavored variety.