Tax, registering etc etc

Hi,

I have searched the forum and found a similar thread to this but it didn't quite answer the questions I have and I'm hoping you guys may be able to help as I don't know who to ask!!

I have recently graduated and worked for a while in a summer job, I was then offered the chance to do some freelance work by a friend for the company he works for and as my summer work was coming to an end I then did this freelance work. After this has followed 2 more jobs one for the same company and one for another company, hopefully more will follow.

All the work was invoiced by me to them and the wages I received for this work has been paid into my own current account either by cheque or direct payment. As the work has paid well and hopefully there will be more of it and I'm an honest person I want to register with the taxman so everything is completely legit.

My questions are as follows:

Do I register as a sole trader?
If so do I require a company name or just use my own name?
Where do I stand in regards to the money being paid into my personal account? is a business account required?
(Obviously I have kept records of my invoices etc and have bank statements)

I probably have more questions but any help with the above would be greatly appreciated, I understand this needs to be done within 3 months of first trading and my first job was 30/9 so ideally I need to sort it out soon!!!