Each Home stack must start with an ace. If you don't have any, you'll have to move cards between columns until you uncover one.
You can't move cards between columns at random, however. Columns must be built in descending order, from king to ace. So you can place a 10 on a jack, but not on a 3.
As an added twist, cards in columns must also alternate red and black.
You aren't limited to moving single cards. You can also move sequentially organized runs of cards between columns. Just click the deepest card in the run and drag them all to another column.
If you run out of moves, you'll have to draw more cards by clicking the deck in the upper-left corner. If the deck runs out, click its outline on the table to reshuffle it.
You can move a card to the Home stack either by dragging it or by double-clicking it.