Some hosting services do not want to go through the trouble of creating the full pathname aliases required to support different domain names. This type of URL looks unprofessional, and is usually too long and cumbersome to fit on business cards and marketing materials. If the ISP doesn't offer full domain name service, look elsewhere. Look for a provider who offers at least 25MB of space, which is standard nowadays. Larger sites may require considerably more storage, espcially if your site has multimedia content.
Most providers charge extra for bandwidth that exceeds a certain threshold.
Find out how much data transfer your plan allows each month and what it costs when you exceed the limit. You should receive traffic reports about visits to the site. There is a wealth of data in those files which can help you fine tune your site to the needs and wishes of your readers. The most common way to update pages is to edit them on your computer and upload the files to the web server with an FTP program. Most large hosting services offer this.