Before the Israelis started "countermeasure", the Hisbollah had in reasonably short time, lobbed some 1.200 missiles at Israel populated areas from within Lebanes area.
Hezbollah fired rockets into Israel up to the Israeli pullout from south Lebanon in 2000. Following that pullout, Hezbollah and Israel engaged in occasional border clashes, usually, but not always, initiated by Hezbollah. They were restricted to military targets.
The only Israeli civilian killed by fire from Lebanon in the period between the Israeli pullout in 2000 and the begining of July was a 16 year old boy killed by an anti aircraft shell fired by Hezbollah at an Israeli aircraft flying over Lebanon. The shell failed to explode and fell into an Israeli village.
On 12th July Hezbollah attacked an Israeli patrol along the border, and fired a small number of rockets at two Israeli military positions as a diversion.
It wasn't until later in the day, at about the same time as Israel began shelling and bombing targets in Lebanon, that Hezbollah began firing missiles at Israeli cities.
The Israeli government gave figures for the number of rockets fired at Israel. As of 20th July, they said between 700 and 800 missiles had been fired by Hezbollah, and gave the following breakdown:
13/07/06 - 125
14/07/06 - 103
15/07/06 - 116
16/07/06 - 47
17/07/06 - 91
18/07/06 - 136
19/07/06 - 116
Total - 734
As they said 7 - 800 missiles fired, there cannot have been a large number on the 12th, and no figures are given for them.