Brian,
If this is your first year of self-assessment, then you'll get the full tax return to complete; most of it will not be applicable to you (unless you have other earnings from other areas, such as property or investments).
Don't be frightened by it, it's still very simple; you don't need an accountant; and a trip to the library will get you a good book called, 'Self Assessment for the Self Employed' which is updated every year. It'll explain other stuff; like what you can claim if you've bought a brand new van.
Next year, if your earnings are under 30K, then all you get is the simple tax return, which looks much less daunting than the full one.
Remember it's called SELF ASSESSMENT, not 'Get an accountant to work it all out for you assessment'. It's simple really.
If you're going to do the paper one, it has to be in by the 31st October now (it used to be the 31st of Jan), but if you do it on-line, you've got till the 31st Jan.
I also pay a monthly Standing Order to the tax man which covers my annual tax bill; and more. I was actually in credit after my tax bill was paid.
