Westwood Bras

Hi, I am a new trader on Ebay selling ladies Lingerie. What I am looking for is someone to advise me on what records I need to keep and to do my tax returns for me. I am currently employed full time by the NHS, I have today completed the CWF1 form, which I understand I need to do to register as self employed, even though I am in full time work. But I really don't know where to go from here and I need some guidance. I am excel and IT literate, I am happy to keep a list of my expenditure but need a bit of hand holding from that stage. I hope that all makes sense. Kind regards Diana