Facing a shady park, the Visitor Centre is the best place to begin a visit to Akko's Crusader sites. Staff can help you plan your tour of the city, sell you an indispensable map (3NIS), show you a scale model of the city and screen an eight-minute introductory film (available in nine languages). Tickets are sold at a kiosk out front (and at both entrances to the Templars' Tunnel); pick up your audioguide at a second kiosk (ID deposit required).
Some really great deals are available on combo tickets that include Rosh HaNikra and/or the Holocaust museum at Kibbutz Lohamei HaGeta'ot.
Seeing all five Crusader sites takes two hours at the very least. Coupons are valid for a year, so there's no need to cram everything into one day.