I hope that you will find the following links
informative and useful:
Foreign & Commonwealth Office (Legalisation / Apostilles)
Faculty Office (which appoints and regulates notaries)
Companies House
Notaries Internationally (Wikipedia)
If you are making a will, please consider giving a legacy to MAG (Mines
Advisory Group, a charity of which I am a former trustee and chairman) which clears land
mines and other remnants of conflict, saving lives and returning usable
land to some of the poorest communites on earth -
MAG Mines
Advisory Group