Travelcard v oyster card? It depends on how much you will be using the tube and buses. But you should bear in mind that the maximum cost of using the oyster card during a day is the same as the cost of the 1 day travelcard - so for most people the oystercard is better and more flexible.

Map - the A-Z guide is probably the best.

Guide - this depends on your interests. And of course a Londoner is the worst person to ask! But the DK Eyewitness guidebook should cover most of your needs.

The rest - I have sent pm.