1. Find an Independent Financial Adviser who specialises in estate planning and who only works on a fee-paying basis (rather than through commission). You'll obviously have to pay for his services but it will be a sound investment.
2. Get hold of the book, published by the Consumers Association, about writing your own will. Study it thoroughly and draft your will. In particular, check that you've answered all of the possible "What if . . ?" type of questions. Here's an example: Let's say that you leave everything to your two sons, Alf and Bert. What if Alf dies just before you? Does his share go to his wife? Or does it go to his children? Or does it to Bert?
3. Now, armed with the advice from the IFA and your carefully thought out will, seek out the services of a STEP-qualified solicitor to tie up all of the loose ends.
Chris