buyToken is not essential to allocate token. You can add all of this in the fall back function itself. Ideally your fallback function must handle this too (consider scenarios where a use transfer ether to your smart contract address).
For sample implementation of ICO contracts please take a look at OpenZeppellin's github repository. There are community audited code there which you can reuse.
https://github.com/OpenZeppelin/zeppelin-solidity/tree/master/contracts
Post ICO the token has to be listed on any of the exchanges Poloniex,bittrex and bitfinex are few examples. Onces they are listed there these tokens can be traded.
You will need a wallet that's compatible with ERC20 tokens to views these tokens. There are many wallets for these imToken is an example you can consider. Parity is good as well but that would require you to have a full node running on your machine.