You can build tableau piles by moving cards there in order from highest (King) to lowest (Ace) alternating suit color. More than one card at a time can be moved, so long as they are all in a valid sequence, ie descending with alternating color.
When the last exposed card of a pile is played, the face down card below it (if any) is automatically exposed.
You can only move a King (with any sequence below it) to an empty column.
Cards from the Stock are flipped one at a time (Klondike) or three at a time (Klondike 3) to the Discard Pile. The topmost card of the Discard pile is available for play to the tableau or foundations.
When no more cards remain in the Stock, you may click it and all cards in the Discard pile are placed back in the Stock.
When dragging a card to another column, you can just drop the card anywhere on the column (not necessarily on the exposed card at the bottom).