Hi Andrew, you could just go to a stock agency's site like Getty, Alamy, etc. find a similar image that is being licensed as rights restricted not the RF stuff and see the cost to license that image in the way you are being ask. For generic licensing / contract info I believe FotoByte is still free, of course your local library has books on photo business and you could get ideas how to write up the contract from browsing the appropriate chapter.
One quick thought, any email where English (or Education) does not seem "like the first language" I would be very hesitant about a 419 scam of course that's your judgement from actually reading this particular email I might also want to use Google checkout or Paypal to make sure I got paid before delivering any full res files. And I would also want to get all their contact info and if you are still wondering give them a call, if they can't provide you with a number, another flag
The good Rev. has sent me countless emails wanting me to photograph an upcoming wedding when they arrive in America ;-) funny cause I'm no wedding photographer I think I'm allergic to formal family gatherings.
Finally stock is different than assignment: There is no act of faith on their part when buying stock you already have the image they want/need wether you are a pro or avid hobbyist you have no reason not to expect licensing the image at the same amount that Getty or any stock agency does, it's after the fact and you are coming from a stronger negotiating point of view not needing to make sales to pay the bills so if it seems like a paperwork nightmare you might want to ask a higher rate.
Edit: some items I would want in the licensing contract:
who is licensing and where is it going to be used/published
the specific number of reproductions
a time limit when they no longer have licensing use of the image
that you retain the copyright
that there is no licensing/usage until you are paid in full
that there is no third party sales