For more information refer to Progressive Networks, home of RealAudio. This is one of the packages which allows Microsoft Windows users to manage their web site without the need to understand ftp and or shell accounts. That will depend heavily on other factors such as how many other web sites are served from that provider, and how busy they are. And also how well connected your provider is to the backbone of the internet. These things are not easily quantified, and I have made no attempt to list them.
Service is the most intagible of all.
It is not unknown for service companies to be incredible responsive to sales requests, but then totally unresponsive when it comes to supporting you once you have signed on the dotted line. All I can suggest is searching around, and perhaps asking for recommendations on newsgroups such as alt.internet.access.wanted or from existing customers of the provider you are interested in. Registering a domain name is quite straightforward in most cases, and can take only a couple of weeks. Some ISPs will offer this service, but assuming you are setting up a web site then I recommend you use one of the providers on the LIST of low cost virtual hosting services. Once you have identified a provider, you will work with them to submit a form to InterNIC who manage .COM domain name registrations.