I'd start by asking your GP to find out whether they have any other trans patients at your surgery, because they may already have something in place but your GP might not know about it. My surgery already has several MtF patients (but I'm their first FtM) so my GP knew exactly where to send me.
I seem to recall that you're based in Blighty. In which case, I've found the GIRES (
http://www.gires.org.uk) website to be invaluable. In their 'Information for...' section there are some documents for medical professionals - the 'DoH publications' link includes an NHS document giving guidance to GPs on the care of gender variant people (
http://www.gires.org.uk/assets/DOH-Assets/pdf/doh-guidelines-for-clinicians.pdf). You can download it as a PDF and print it for your doctor - but in my opinion, they should be doing the research themselves; it's not your job to tell them how to treat you, other than letting them know your personal preferences such as pronouns etc. Also, there doesn't seem to be a nationalised procedure about what to do & where to send you so they'd need to check with the local authority or healthcare trust.