Yes, there are and his name is "saintpeter48". Sorry to be sarcastic, but what I mean is that you can do it yourself. I made mine about 15 years ago, and I am still alive! I am glad to see you are taking this seriously, and not saying "Die, that is the last thing I would do". I must stress that you should buy a proper will form from any good stationers (mine cost 65p) and I understand Smiths stock them. Next you have to type out the whole thing without one single mistake, if you do you will have to do the whole thing again. Finally must sign and date it in the prescence of 2 persons of character, so no M.P.s then. This 2 persons must not see the contents of the will, and they have to sing 2. This is all perfectly legal, and above board, but really only works if your affairs are very simple. The best thing to do is to leave it all to one person or trust. In this instance you must state" I xxxx leave my entire estate absolutely and benificilly to yy". Then state whether you want to be buried or cremated.
Failing all this you can get the services of specialist will firms who will do it all for you, and store it (the important bit) for under �40. I think that this is very good value, as one single mistake in the above mentioned conditions will render your will invalid as will marrying after making this will.
Message to all those considering making a will, get it done, when you die it is tool late. You are not signing your death warrant.