share valuations for probate??

eccleskirstn said: "Hi, My mum recently passed away and i'm trying to gather the information needed for probate of her will. She held a number of shares and I need to find out the value of each at the date of her death. However being a novice i am totally confused wth buy, sell, bid, offer, ask!! I imagine i need to find a 'sell' price? I can only find closing prices for historical values. Can anyone throw any light on which price I would require and how best to find this?! Thanks in advance! K"