Marseilles

marseille-tourism.com. Has lots of useful stuff. Click on the Union Jack (British flag) in upper right corner.

Chez Fonfon is good for a bouillabaisse, although I haven't been for a long time. I have heard that l'Epuisette is too. They are in a little inlet called le Vallon des Auffes. The restaurants serving bouillabaisse on the Vieux Port are overpriced for what they serve (albeit cheaper than the two aforementioned ones, but not as good).

I don't know if there are walking tours of the Vieux Port but in the vicinity I would recommend visiting St Victor's Abbey (the crypt is 5th century with many interesting early Christian sarcophogi and sculptures); the quarter of le Panier (the original part of Marseille although sadly a third of it was demolished during the war); the MuCEM (Museum of European and Mediterranean Civilsations), which also encompasses Fort St Jean; if you fancy a break there is a brasserie called La Samaritaine which is on the north-eastern corner of the Vieux Port and you can sit inside or outside on the terrace and have a drink, the building is a mid-19th century one but it has a kind of early 20th century vibe to it, waiters in black and white etc. La Caravelle a bit further on is nice too, they have a (small!) balcony overlooking the port and serve tapas in the late afternoon.

Rick has a full chapter on Marseille in his Provence and the French Riviera book (including an Old Port walking tour), see

http://travelstore.ricksteves.com/catalog/index.cfm?fuseaction=product&theParentId=158&id=165

RS Provence & Riviera book covers several destinations that are not in the France book, Marseille included.

Ian has sent you in the right direction for bouillabaisse. I'd be very picky and rely on the Michelin red guidebook for bouillabaisse. If you aren't careful most of the time you'll be getting fish soup made in a factory--which is quite good, by the way--but not the authentic bouillabaisse, which has become quite rare (and pricey) these days.

You might be able to get the Michelin recommendations and look up Ian's recommendations on viamichelin.com.

If you aren't really looking to spring for the real thing but just want fish soup, as I said, most of it comes from a factory but it is quite well made for what it is.

Helpful comments, especially re bouillabaisse.

The walking tour on the http://www.marseille-tourisme.com/en/ website looks interesting.