IMO, hosting a website from a homemade (and home-based) server is not a great idea. Firstly, many ISP's do not allow you to do this, so IF you do decide to build your own server, I highly recommend checking with them first. Secondly, the amount of work that comes along with building a server is quite a bit (constantly upgrading the software, protecting + securing the hardware, back-up power systems, etc). Please note that most (or all) of the above are taken care of by the DC when you purchase a dedicated server (depending on the management plan), or use an account from a shared hosting provider. Now, if you plan to create a server just to play around with things locally (on localhost), then that's fine.
There are many other reasons as to why I strongly suggest not creating a web server, but they have already been mentioned in this thread. All I will say is this: be careful!
Chris