Getting there and away: see Nagasaki post Getting around: Fukuoka has an efficient metro service which charges based on distance traveled, starting at 200Y. There is a central loop bus that costs 100Y and is extremely popular and crowded on weekends. Multiple train lines spoke out to all the rest of Kyushu and beyond.
Resources: the Lonely Planet was a decent starting point, but much more information is available from the English language brochures available at Hakata station, particularly the green "Fukuoka City Visitor's Guide."
Where to stay: there are lots of inexpensive business hotels around Hakata station. Listings are available at the tourist info desk. We stayed at the Green Hotel for approx 7600Y a night for a tiny but tidy room.
What to eat: Fukuoka is a ramen mecca, and is renown for its food stalls on wheels called yatai. We had a memorable food stall dinner just south of the Oyafukodori and Showadori intersection. There was no English menu or English spoken, but we managed with the point and shoot technique, which works particularly well when other patrons are eating something tasty. We had a sampling of yaki-ramen, yakitori, and cabbage roll oden, along with two frosty Asahi Dry beers (total bill under 2400Y). At lunchtime we found ourselves sucked into the vortex of the immense Canal City shopping mall, which seems to have out-competed all the restaurants in a 500m radius. There must be a hundred different restaurants in the mall, and we went to a Korean one the top floor and had a halfway decent bimibob and glass noodle with beef.
What to do: with only 24 hours, we didn't do the city justice. This is a consumerist town, and many of the major attractions listed in the City Guide are essentially shopping malls. Tenjin area is the central business district and city shopping hub, and 
is lively in the evenings. We took a ferry from Bayside Place (a failed waterfront development and ferry terminal) to Uminonakamichi, a peninsula across the bay. The ferry ride is a nice opportunity to marvel at the ambitious commercial waterfront developments - Fukuoka tower, Hawks Town and the Yahoo dome, Marizon. From the ferry terminal it is an approx 400m walk to the entrance to the seaside park (400Y pp) which has biking and walking trails, picnic areas, flower gardens, rides for kids, and a nice viewing platform out over the Sea of Genkai. The JR train line back to Hakata is just outside the eastern gate to the park, with a train about every 30min.
is lively in the evenings. We took a ferry from Bayside Place (a failed waterfront development and ferry terminal) to Uminonakamichi, a peninsula across the bay. The ferry ride is a nice opportunity to marvel at the ambitious commercial waterfront developments - Fukuoka tower, Hawks Town and the Yahoo dome, Marizon. From the ferry terminal it is an approx 400m walk to the entrance to the seaside park (400Y pp) which has biking and walking trails, picnic areas, flower gardens, rides for kids, and a nice viewing platform out over the Sea of Genkai. The JR train line back to Hakata is just outside the eastern gate to the park, with a train about every 30min. 