Very good question. This is always the stumbling point with cryptos in general. As far as I know Blocktrades are still allowing purchasing of Steem. Another alternative is Shapeshift - although it depends on how much Steem they have available at the time you trade. I think the Steemit team and some others in the community are looking into other options for buying but it is always tricky due to the local laws that relate to AML/KYC. I think Bittrex is still one of the better options but as you said it is difficult to explain to someone who is new.