If you're going to eventually withdraw the funds, it's easiest to do it through Coinbase (for small amounts) or Kraken (an exchange, for large amounts). I give a guide to setting up on Coinbase at https://steemit.com/steemit/@mark-waser/newbies-guide-to-powering-up and it is currently possible to get $110 dollars of bitcoin + up to 9 SBD for $100 (less the normal Coinbase fees, of course -- but fees are everywhere and you still end up with over $105 dollars and up to 9 SBD).