There is a huge range of authors and activities. The festival opens with a book swap, and continues with plenty of fiction, non-fiction, poetry and children's events. I'll definitely be going to a few, and I should think there's something for most tastes. See the full programme here.
Finally, if you're a budding poet aged 14 or under you may want to enter the poetry competition. Submissions in any format on the theme 'Lewisham' will be judged by a panel of poets.