I am new to this site hence the late reply.
Re the tax and vat.
on the tax/ nat ins you register as a sole trader via a form from your local tax office and pay nat insurance by direct debit £3.50 per week approx.
you can become a sole trader along side your full time employment.
Actual income tax payable is based on the income from your business and should be declared to the tax office on self assesment form,then you will recieve tax bill.You do not need to register fo vat unless your turnover exceeds approx £53k.Down side to this is you can not claim vat back on your materials but in turn you do not need to add vat to invoices or do time consuming returns.
You possibly have all this information from elsewhere by now,but if not I hope it helps.