If someone asked me "right now" and they didn't have unusual hardware needs, and they were dipping their toes into it, I would suggest wholesaleinternet.net and get 1 or more cheap servers to practice with. I rent something there for about $25/month, though you can get a better setup for a bit more.

When you have a better handle on what works for you, then go with colo (meaning you don't rent servers, but buy and setup your own servers and Ethernet switches, that go into your rack space).