Not a prob, and welcome :) Steem dollars are firstly awarded from blogging rewards say you make 2 dollars, 1 dollar will go to steem power and the other to steem dollars. Steem dollars are pretty much dollars, you can transfer them out of steemit immediately and transfer them on an exchange to dollars, OR which i prefer doing - is use them to buy more steem power (you can do this buy just clicking buy or sell on the steem dollars option)

Hope this helped