These can be anything from icons, images, logos or the overall design colour palette. I can, and do provide all of the services to get everything in one place, but to keep your prices down it's always a good idea to have all of this ready to go, so I have a clear canvas to work from. These should include: Logo - Colours - Fonts - Icons - Images - Artwork
A new site is easier in some ways that there is no existing data to cater for, no potential downtime or dealing with an existing hosting environment, but there's also more work involved as an existing site usually has some or all of the copy in place to port across, many times it has an exiting architecture, logos, photos, artwork etc.
Also an existing site owner will have been through this process before, so it a little bit more attuned to the requirements.
Some existing sites may have some if not large amounts of data they wish to port across. This can be anything from simple blog posts or other data that they wish to include in the new site.
Is a domain name required, or do you already own a domain name. Will you require hosting or any other technical assistance like moving hosting provider.