You should start by reading this page of advice by Henry Cohn:

http://research.microsoft.com/en-us/um/people/cohn/Thoughts/advice.html

As it says there (among many other useful things), you should prepare a paper using LaTeX. It takes some time and effort to learn LaTeX, but it is much easier to learn LaTeX than to prove a valuable theorem. In practice, academic mathematicians will use this as an informal test: if you have taken the time to use the standard tools, they will be more willing to take you seriously.