Self employed and confused on different filing dates and years between UK and US

I've lived in the UK for about 4 1/2 years now. I have not had to file taxes before now as i have not worked until 2012. I am registered as self employed now. I work for an America doing video editing. I know the American tax year for 2012 is 1 Jan-31 Dec for filing in 2013. I do self assesments and have found the tax year is differant than that of the US. I am really puzzled over how and when to file in the US if I don't file in the Uk till much later. I have only made about $10,000 which will be under the threshold for paying taxes here in the UK. Do i actually fill out a tax form for filing in the States? Or is it all part of the form i will use when I fill out my Uk tax forms.
To make it even more complicated, my us ss# is still in my previous name but I work remotely from the US in my new married name. I have no idea what i should be doing and don't want to have to spend big money in order to get such small earnings sorted. Can someone point me in the right direction? Many thanks ahead of time.

I am afraid that you have to manually work out what you earned/ your expenses for the different years. It is a pain, but for your US returns you do 1st Jan 12 to 31st Dec 12 and for the UK one you do 5 April 12 to 5 April 13.

It can get complicated so you need to keep clear records of when things were earnt etc.  You also have to add up bank interest etc according to when it was earned.

I am afraid that you have to manually work out what you earned/ your expenses for the different years. It is a pain, but for your US returns you do 1st Jan 12 to 31st Dec 12 and for the UK one you do 5 April 12 to 5 April 13.

It can get complicated so you need to keep clear records of when things were earnt etc.  You also have to add up bank interest etc according to when it was earned.

+1 yes you just have to do the math.

Just to check do you invoice the US company? so you are not paying FICA or US tax at source!