If it's a learning experience, you should get a virtual server to which you have full access. This will satifsy your need to learn, and shouldn't cost much. You should then have your own IP address. There's no way to predict what an overzealous block list could include - they could deduce that you share a network or an ISP with a porn site. The "legitimate" censorship software generally relies on hostnames and URLs, but there is a lot of this out there.
You may wish to consider running a server at home instead of paying for a virtual server. This depends on what Internet connectivity is available in your area and what hardware you own. Cheap virtual servers can be similar to home Internet connectivity - luck will play a major factor in their customer service and in their reliability and performance. Overzealous censorship blocking lists could also include ISPs that provide service to home customers, if you're worried about ones so excessive that they block by IP address. I would just ignore this for now and see what problems you run into later, it's rarely a serious issue, and always the client's fault for using unreasonable blocking software.
It sounds like one of your questions is "what does an HTTP request look like, and how does it specify the hostname". I think it's good to start from a low level like this. The Wikipedia HTTP article should give you a reasonable overview and point you to appropriate RFCs. Since you seem interested in low-level details, which is indeed necessary for a proper understanding, knowing a bit about TCP and DNS would be helpful, but you probably don't need to fully understand them. If it's Web Hosting 101, about 10 minutes should be spent on TCP and 10 minutes on DNS for every week spent on HTML.
I think the real question here is - what's a book that discusses all of this, from the ground up, with an reasonable balance of detail. Many people here learned this stuff ad-hoc, possibly as the technology was developed. Some others may have learned from schools. This can make it hard to provide guidance to someone learning fresh. I'm curious about myself, in case I get asked this myself by someone who's willing to learn.