Erin Logsdon (@taxonomylady) wrote a blogpost with some great tips how to give your library a twitter makeover for follow a library day.
Having a complete profile (Location, Web, Bio) is important for two reasons. One, the text in these fields in keyword searchable, so it will help people find you if the information is complete and relevant. Two, people use the profile information as a contextual way of understanding who you are and the purpose of your Twitter account. Can they ask you a question via Twitter or do you only use the account to push news stories and other content?
Adding the name of the person responsible for tweeting in the Bio is a great way to add a human element to the account. It also lets people know who to contact if they need further assistance.
Read all the makeover tips from Erin on Beyond Sliced Bread