Hi John, if you are going to do it properly then it is not simple straightforward and uncomplicated.
There are a lot of factors to consider from carrying out a proper assesment of the building to acually making sure what you buy/manufacture is suitable.
The best place to start is to buy a copy of the Sign Design Guide available from the JMU or RNIB cost £20.00
This will give you some insight as to what is required if the job is to be done right, they have already started putting up braille and tacktyle signs in Fife where I live and I havent seen one done correctly yet. I wonder who is responsible, the local Council who ordered the signs or the signmaker who produced them.