The Draw Phase is the first part of the Corporation's Turn. There is a paid ability window right when the Corporation's turn starts. Then conditional abilities with the trigger "When your turn begins" are triggered. Finally, the Corporation player draws one card.
|Page 12, Column 2, Paragraph(s) 1-2, Core Rule Book|
|The Corporation draws the top card of R&D. This does not cost the Corporation any clicks.
Note: If the Corporation's R&D is empty when he attempts to draw a card, the Runner immediately wins the game.