I'm not clear from your question on the kind of information you are after, but here are some pointers: make sure you have appropriate insurance in place (professional indemnity etc), make sure you draw up/get a solicitor to draw up a standard contract and terms and conditions. Make sure you this contract is agreed and signed before you undertake any consultancy work for anyone. A solicitor can probably draw one up for you for minimal cost, as it need only contain standard terms or you can have a go at drafting it yourself making sure to cover things such as - definition of your services, performance of services, charges/fees, exclusion clauses/limitation of liability, confidentiality, data protection notice (if appropriate), duration, termination, intellectual property (applicable if, for instance, you will be creating marketing material - need to make it clear who owns the moral rights to that material, you, as creator, or your customer).