National Landlords Association - NLA website, this is a very useful site and membership to this organisation is highly recommended for landlords, its run by landlords for landlords and help and guidance is available for every step of being a landlord.

The Property Ombudsman - Ombudsman of Estate (and letting) agents, this is the main regulator for our industry and most good agents are members of this body, if they are not they may have something to hide! beware!