The Draft happens in the offseason, somewhere in the first week of June I guess.
Right now, check the results of the hard work of your scouting team through the edit draft order in
http://www.buzzerbeater.com/BBWeb/draft.aspx and after that the draft will automatically happen, and you don't have to do anything.
Just an additional question for other people, who is more worth drafting, a player with skill A- and 2 ball potential or B+ skill with 4 ball potential?