Excel is great if you use a basic template, which you could get set up easily by your accountant, or by a freelance accountant.
A free accounting software which is quite good is MS Accounting, you can download it for free.
Hi,
You should register with the HMRC to let them know (within 3 months of the start date). You will have a fill in a tax return every year (which they will send to you). Just keep all paperwork related to the income you make and expenses you might incur, which you can deduct and get tax relief on.
Ingrid
