Hello! You can read the documentation and get all the necessary information on this link. If you have any additional questions - ask in the appropriate forum thread. http://solidity.readthedocs.io/en/latest/
Firstly, you have to lears JavaScript, as Solidity (erc-20 contract language) is build on JS. Good option to do it might be codeschool.com After it, find documentation of solidity and just learn diffferent functions and so on. Good luck!
Investment in BTG was my one of the worst decision. Bought it at a rate of around 250$. It went around 400 few times, but didnt sell. Now it ate all my money i invested on it