Web hosts offer a range of hosting plan features to attract customers. These include disk space, e-mail boxes, auto responders, FTP access, free bandwidth, templates etc. It is for you to decide which hosting plan suits your needs best.
Your first requirement is space. You need to decide web space based on the volume of content you plan to host & also the kind of content that is to be hosted. You will need more space if you plan to host images, graphics or audio files.
The next big requirement is bandwidth. It is important to purchase sufficient bandwidth to cater to your traffic. In the earlier years of the net, bandwidth was a major resource constraint. Today, with excess bandwidth attainable most web hosts offer as much as 1,000 GB of data transfer free.
Some web hosts offer web analytics too. This is a very useful service to buy because it gives you an insight into the way your site is being used. You learn the places from where the traffic is originating, the pages that are being read, the amount of time a visitor is spending on your sites, the search engines that are sending the traffic etc.
The log files that are used to do traffic analysis take up valuable space. With daily logs, you can download and delete them, every day. However, if you have monthly logs, you will not be able to delete them till the end of the month. Sometimes, the web host includes this space in your server space. Please clarify this point or else you may end up losing several megabytes of space over a period of time to log files.
You also need to check if your server space includes space for e-mail boxes. If so, you must set a maximum limit for each mail box. This can save you from exceeding your storage limit.
If you are setting a business site then you must ask for auto responders. This little software is very useful for sending automatic return mail to visitors who show interest in your site. Similarly, forwarding aliases can be useful if you want to send your e-mail to a filter program, before it reaches you.
Also, make sure that your hosting plan includes FTP access. This is very important because you cannot host content without FTP (file transfer protocol) access. Most web hosts don't charge anything for FTP access.