Norwich is home to Norwich City Football Club, who play in the top tier of English football "Premier League". Its ground, Carrow Road, is fairly close to the city centre and a 6-10 minute walk from the railway station. The ground seats 26,000, and if you visit Norwich and are keen on football, it's worth a visit - a friendly ground, with large amounts of family spectators.
Norfolk and Norwich Festival
Norwich is the key site for the Norfolk and Norwich Festival (http://www.n-joy.org.uk) held every year in the month of May.