A question

Can any of readers enlighten me as to how the process of creating a government in Spain happens? I'm wondering about the period we're in now, where Zapatero is still being referred to in the media as 'Prime Minister-elect'. I assume the system is similar, but not identical, to that in the UK, where he has to show he'll have a majority in the parliament, but by what process does he become Prime Minister rather than Prime Minister-elect? Is it elected by the new parliament when it first convenes or is it, as in the UK, at the invitation of the King?

Update: Thanks to Matthew in the comments for the link to this page which gives most of the answers I was looking for. It seems quite similar to the role of the monarch in the UK:

The king sanctions and promulgates laws that have been worked out by the other branches of government. He formally convenes and dissolves the Cortes and calls for elections and for referenda. He appoints the prime minister after consultation with the Cortes and names the other ministers, upon the recommendation of the prime minister. He also signs decrees made in the Council of Ministers and ratifies civil and military appointments.

However, the Prime Minister is chosen by the parliament before being invested by the King:

When the prime minister is appointed following elections, he must present his program to the Congress of Deputies and receive a vote of investiture by absolute majority before he can be sworn in by the king. If he cannot obtain a vote of confidence for investiture, a new vote is taken forty-eight hours later, requiring only a simple majority.

There's some interesting notes in there about how Juan Carlos' personal actions since the death of Franco have defined the monarchy in its limited role - I can recall a couple of soc.history.what-if discussions about what might have happened in Spain post-Franco if he'd been a different character.