Hello
I am going to kew for the first time in a couple of weeks and have read all of the advice here and in other threads but i would like to know if both myself and my partner need a readers card, are they for entry or just to order documents?
That depends what you want to see. They are not needed at all for the computer search room, including the 1911 area, although you will have to go through a less comprehensive security and leave all your no-no stuff in a locker for that, so still follow the advice above about what papers to take and how.
However, if you want to see any originals, you will need to book a seat(s) in the reading rooms and have reader's cards to go through the additional security to get there. Your documents are then booked for use at that particular desk(s) and arrive in a postbox just for that desk. You have some choice over seats so I think that you should be able to book adjoining seats but I think that you can't access that area at all without both the card and the seat already booked.
The cards are useful to have anyway as you can charge them up for your printouts and even order printouts and then pay on the card before the printing is actually done.