I am considering buying an established business which has been created and developed over 5 years. . The business is in children's entertainment and the business has a very established contact list and pre weekly booking which are set up. My concerns are around keeping this business running, legality, copy right, ownership etc. Can anyone shed some light on my thoughts? Thanks!

What about his business is already copyrighted, if so your puchase agreement merely buys any of his copyrights also.
Also you will want an agreement were the seller can not open up a similar business in the same area. But often it is the personality of the owner that works the business, and you can expect to lose some customers