I took the following from the U.S. State Department website.
http://www.state.gov/r/pa/ei/bgn/2019.htm
It describes the Costa Rican government and a bit about the legislative process. I highlighted a section that talks about Sala Cuatro (the fourth room). I am not exactly sure about the specifics but, as I understand, this is a branch of the Judiciary that reviews all legislation passed by the Chamber of Deputies. I find it interesting because it is so powerful. It is like an ultimate super veto player with final authority over all legislations. However the one limit to its authority is that it is purely reactionary, like the U.S. Supreme Court. If anyone has any insights into Sala Cuatro and its significance please feel free to add comments.
GOVERNMENT
Costa Rica is a democratic republic with a very strong system of constitutional checks and balances. Executive responsibilities are vested in a president, who is the country’s center of power. There also are two vice presidents and a 15-member cabinet. The president and 57 Legislative Assembly deputies are elected for 4-year terms. In April 2003, the Costa Rican Constitutional Court annulled a 1969 constitutional reform which had barred presidents from running for reelection. As a result, the law reverted back to the 1949 Constitution, which permits ex-presidents to run for reelection after they have been out of office for two presidential terms, or eight years. Deputies may run for reelection after sitting out one term, or four years. In October 2007, the country ratified the U.S.-Central American-Dominican Republic Free Trade Agreement (CAFTA-DR) by a slender margin in its first national referendum.
The electoral process is supervised by an independent Supreme Electoral Tribunal–a commission of three principal magistrates and six alternates selected by the Supreme Court of Justice. Judicial power is exercised by the Supreme Court of Justice, composed of 22 magistrates selected for renewable 8-year terms by the Legislative Assembly, and subsidiary courts. A Constitutional Chamber of the Supreme Court (Sala IV), established in 1989, reviews the constitutionality of legislation and executive decrees and all habeas corpus warrants. The next national elections will take place in February 2010.
The offices of the Comptroller General of the Republic, the Solicitor General, and the Ombudsman exercise oversight of the government. The Comptroller General’s office has a statutory responsibility to scrutinize all but the smallest public sector contracts and strictly enforces procedural requirements. Along with the Sala IV, these institutions are playing an increasingly prominent role in governing Costa Rica.
There are provincial boundaries for administrative purposes, but no elected provincial officials. Costa Rica held its first mayoral elections in December 2002, whereby mayors were elected to 4-year terms by popular vote through general elections. Prior to 2002, the office of mayor did not exist, and the president of each municipal council was responsible for the administration of his/her municipality. The most recent nationwide mayoral elections took place in December 2006. Autonomous state agencies enjoy considerable operational independence; they include the telecommunications and electrical power monopoly, the state petroleum refinery, the nationalized commercial banks, the state insurance monopoly, and the social security agency. Costa Rica has no military and maintains only domestic police and security forces. A professional Coast Guard was established in 2000.