This looks like a useful resource. Moneymadeclear, the financial information service from the Consumer Financial Education Body has a microsite dedicated to providing impartial financial information for those going through separation or divorce. The site contains all sorts of practical financial advice, ranging from costs, through maintenance to dividing property. It even includes a 'Divorce and Separation Calculator', which will help you to 'draw up a budget; work out what you have and what you owe; and look at how you might split what you have', although I've not tried it out.
[Thanks to Divorce Saloon for the heads-up on this.]