Jargon and acronyms should be kept to the absolute minimum, or if they must exist, they should be metatagged with common english counterparts eg. Penalty Charge Notice should be crossindexed with parking fine and parking ticket.
Think about your users - organize information in ways that make sense to them, not in ways that match your organizational structure!
The home page should have a list of links that cover the main user tasks, as well as allowing the user to search by keyword, subject area, and offer predictive results as they type.
The search engine on the site should be prominent and *work* - ie not produce lists of thousands of PDFs or word documents.
A council's website should publish data in open formats which can be resused by external bodies or individuals.
This should be a no-brainer, but sadly it appears not to be. Yes there will always be problems no matter how much testing is done, but NEVER launch a site without ensuring that the majority of links work and that most of the pages contain content.
Use http://getsatisfaction.com to collect problems and suggestions in one place.
Then have people employed to answer them, and engage in a conversation about the most interesting ones.
Ask for testers from the community that will/do use the site. Go out and seek people with different technological and physical capabilites and needs and build up a strong and diverse user testing base for invaluable, direct, practical feedback.
A council website should support users needing grassroots 'community' information and could engage more effectively if it had a companion portal (or even better - as part of its main site) for communities, business and residents to participate with; much like the model at - http://www.citysoup.ca
All pages on the website should make it easy for the user to vote as to whether it was useful or not, so poor content can easily be identified by the web team.
Services that poke you when something of interest happens and help you sort something out when you are annoyed. Council websites should not be destinations/portals.
Tell people when a link is going to a PDF and include the size in KB/MB