What will it cost?
That's rather like asking, "how long is a piece of string?" but it's the question that tends to be uppermost in peoples' minds so let me give you some idea of what to expect. Firstly, there are two costs involved for any website, much as there are for houses or cars: capital and revenue. Building the site itself is a "one-off" process that can be regarded as a capital cost. However, the site will need to be "hosted" on a web server, and it will need an internet address, known as a "domain name". Both of these things have to be paid for year on year as a revenue cost. You should add to that an annual cost for maintaining your website. Nothing stands still in the world of information technology. Software needs to be updated constantly; content and other data need to be backed up regularly; links have to be checked repeatedly because the internet is a dynamic place where the boundaries are constantly moving.
Domain names cost anything between a £5 and £20 per year, depending on which registrar you use, and what type of domain name you want. ("Top" level domains - such as .com or .org - cost more than second or third tier ones - co.uk or org.uk.)
Hosting packages cost anything from £40-50 per year up to several hundreds of pounds per year, depending on how many supporting technologies you need, how much web-space and bandwidth will be required, and what level of backup and support you want.
Building costs vary enormously, mostly depending on the size and complexity of your site and the number of employee-hours required to get it up and running within your time-scales. Reasonable charges are likely to start at a few hundred pounds, but can easily run to several thousands if you need a large, multi-functional site that is going to serve thousands or millions of people. A significant factor in the building of any site is likely to be the cost of the design. This covers the "look and feel" of your site, from a logo and colour scheme, to the type and size of font that you use and the level of sophistication that you think is appropriate for your business or organization. Costs start at around £20 for an "off-the-shelf" template, and can run to many thousands for a customized, professional design package.