The UK Hydrographic Office has for a number of years now had a great website where information regarding charts and sailing directions can be found. They have now added a great tool which can be downloaded
here
This tool is a combined digital chart and publications catalogue, including Tide Tables, List of Lights, List of Radio Signals etc. as well as being a passage planning tool. IMHO it is great as it makes identifying the charts needed much simpler. I strongly recommend it.
Also,
click here to download NP100, The Mariner's Handbook in pdf format.
Well done the Admiralty!
Aye // Stephen