I am travelling from the UK to America but I was told I need to fill out...

[robinb]

Yes, first go here:
http://www.britishairways.com/travel/usawaiver/public/en_gb
This is the information you need,

Then go to:
https://esta.cbp.dhs.gov/esta/esta.html?_flowExecutionKey=_c6B531EFB-A6AE-FADE-A5CE-59A5FA3286E1_k57575229-85E0-DD9F-F59E-9C439B04EBE0

 

[Gudasz]

...a form,does anyone know about this? and if this is so where can I get this form from?

 

[VictoriaR]

I went to New York from the uk about 3 years ago, and had to fill out a form on the plane to be allowed in the country. The air hostess' handed out the forms and you handed it in to customs when you arrive.