Filing Taxes

I've been in the UK since August and have earned less than £5000 since I arrived here.

My earnings (from unemployment) last year in the US was around $2000.

Do I have to file taxes?

If not, great, if so, where do I file, is there anywhere I can do it for free?

I don't remember what the requirements are, but a quick google and you should find the information. IIRC, however, seems like it's always best to file whether or not you owe any money. The free way to do it is just get the IRS forms online and fill them out. We buy Turbotax.