i'm sorry, i also forgot to add that the CDU, Merkel's party, lost 1.4%.
http://www.spiegel.de/politik/deutschland/0,1518,651389,00.html
above is a link to the election results. on the left are percentages. on the right are seats in parliament. you may notice that although the CDU/CSU lost %, they gained seats, because of the 5% rule. the 5% rule means that any party that does not pass the 5% mark in the election does not get a seat in the parliament. there are, however 5% of the total amount of seats left open for these parties, which are then filled by representatives for these parties. the 2 buttons on the top are the following [Zur Erststimme]/[Zur Zweitstimme] ([to the first vote]/[to the second vote]) and [CDU/CSU getrennt]/[CDU/CSU zusammen] ([CDU/CSU seperate]/[CDU/CSU together]).
1st button - there are 2 votes in the german election: one for a party (1st), one for a candidate (2nd). these determine who fills a parties spots in the parliament. those people who are elected by the 1st vote are directly elected to parliament and take up spots allocated to their party by the second vote. if the second vote guarantees the party more spots than 1st vote members are elected, the party can fill these spots with people they select. however, if there are more members of a party elected by the 1st vote than by the 2nd vote, those people might still get to serve, depending on how many parties did not pass the 5% mark (theres a big discussion going on in germany right now as to the legality of this, so it might change in the not-so-distant future).
2nd button - CDU and CSU are the christian democratic union and the christian socialist union. basically the same party, at least nationally. basically the CSU is the bavarian (bavaria is a "state" of germany) division of the CDU, and they have the same agenda. however, they still have separate party leaderships.
i hope all this writing doesnt put you off. any questions i will try to answer to the best of my ability. i am a german/us citizen and currently studying international and european law in the hague, netherlands.