Iain,
This will give you a month ahead.
Tidal predictions
Someone posted a "free online almanac" this morning - which I suspect is the one mentioned/advertised in Sailing Today this month which I've been meaning to look at.
EDIT - no its not the one in ST - which is
www.sailingalmanac.com - which looks to have OK marina type info etc but just takes you to Easytide. The site referred to this morning (
www.visitmyharbour.com) does the same but didn't seem too well designed.