Augmented Reality (AR) takes bits of digital content, most commonly visual graphics, and tries to make them seem as though they're part of the real-world. One use could be to provide x-ray glasses that allow you to see the electrical wiring in a building, for easier maintenance. Another use could be populating your local neighbourhood with virtual goblins to lay the smack-down on.
It is important to have realistic expectations. AR is not yet at the commercial level that allows you to put on a pair of glasses, and feel like you're inside World of Warcraft. Instead you'll be wandering around with your smartphone, looking at a video feed from the camera, and at certain locations you'll see 'something' that you can interact with. That very vague description is because this can be anything that you want it to be.
There are an increasing number of AR platforms that you can create content with, but I'll initially be covering use of Layar.
Anyone with an interest in Augmented Reality. Specifically it's the Layar platform, but you'll get a general idea of how location-based AR works. You'll probably need at least some experience with programming languages. You probably won't learn anything about MMORPGs.
To make things as easy as possible, you'll want to look for hosting that at least includes PHPMyAdmin (for creating and administering your database), and something like CPanel (for everything else that you'd need to do on the server). You might be used to testing things locally using a server running on your computer (e.g. XAMPP), but in this case it needs to be visible to the rest of the world to work. If you know how to do that then that's fine, but I won't be explaining it. These instructions are for PHP and MySQL, so if you're following exactly then you'll want to check that they're supported (I'd be amazed if they weren't).
Recommendations are tricky, but there are different options based on your budget. If you want something completely free, then you might look at a company like x10hosting - where they even supply you with a free domain name. I've used them before without any problems, but in general you should be cautious of anything that is completely “free”. If you want to buy a domain name (~ £4-£10/5-12EUR a year), then there are a lot more options for free hosting. I pay for hosting on 5quidhost, but they also have a free plan. If you can spare around £40/50EUR a year for paid hosting, then the world's your oyster.