You are required to register for VAT if your turnover meets or exceeds £61,000. This will increase slightly in April.
If you do register, find an accountant by recommendation as this will really simplify the whole process and ensure your accounts are properly kept. Assuming of course you are not an accountant!
A book keeper may suffice, but personally I always preferred a chartered accountant as they have much more in depth knowledge of tax relief and should save you at least their fee etc. It shouldnt cost more than £600 per year to have someone look after all these affairs for you if you keep proper records.
We prefer dealing with VAT registered businesses because it shows substance to a business. If a trade customer is not registered, we usually ask for more extensive identification.