I registered as a self-employed sole trader in January 2010, so only in business 9 months. Is it correct that I don't have to file any kind of return until next year October 2011? I was planning on doing it online myself.
Yes that is correct. Did you register for VAT? Not sure if that will make a difference.
But as a sole trader myself (not registered for VAT) I know you don't have to make any return until next year for your 2010 income.
You will need to keep reciepts and you should make sure you are claiming for whatever expenses you are allowed to, you might need an accountant to help you on that.
As you commenced in 2010, you also have the option of preparing 21 months accounts up to 31 December 2011 and filing your 20010 & 2011 returns by 31 October 2012.