As Tim says, all the info is on here somewhere.
However, a colleague recently collated it all for me, so I might as well share with you:
1. Send the form linked below to the CAA, not forgetting your cheque for £16.
2. Give it time to get there (couple of days), and then fax the FAA form (also linked below) to Oklahoma City.
3. Sit back and wait for the letter from the FAA* to drop onto your doormat.
You don't actually get any docs from the CAA - your form and funds are to to authorise the CAA to respond to an enquiry from the FAA.
*(The one that you will present at your designated FSDO in order to get your Temporary Airman's Certificate, which you can fly on immediately - the "real" license (sic) will arrive in UK a few weeks later).
CAA Form:
http://www.caa.co.uk/docs/33/SRG1160.PDF
FAA Form:
http://registry.faa.gov/docs/verify61-75.pdf
Other Handy Info:
Locate an FSDO:
http://www.faa.gov/avr/afs/fsdo/index.cfm
FAA info "Foreign Pilots: U.S. Certification":
http://www.faa.gov/avr/afs/flightinstruction/index.cfm
Note also that the letter you get back from the FAA to present at your chosen FSDO is only valid for 6 months.
Onan's point about flying with an instructor is well made, but you will need to do that anyway in order to be able to use your US licence/license, as it is an FAA requirement that you are in date for your Biennial Flight Review - an hour's ground school and an hour's flying with an instructor.
I suggest you buy and peruse Jackie Spanitz's "Guide to the BFR" (
Available from Amazon UK at £8.05); also worth getting hold of an FAA chart ("Sectional") to familiarise yourself with before you go.