Phil- This isn't meant to sound patronising, but I have to work with the facts you give. The 'help' file (what you originally referred to) meant more of a function of the program (to me) than a 'readme' file, which is obviously text based info. Maybe my mistake, but perhaps your first lesson in ATC- assume nothing- as has been pointed out already by 250kts.
I don't know that you're not that stupid- its not personal!
I've searched for a manual for you, but no luck, sorry.
However, I do have some suggestions about your choice of future career- get an airband radio, search the internet for info, and make a visit or two to ATC units- if you can prove yourself knowledgeable and proactive, then you'll have a better chance than someone who has 'just' played an ATC PC game, IMHO.
If you're already doing these things, then good.
Out of interest, whats the attraction in ATC?