Stop. Seriously, just stop.
Impeachment is the civil punishment of a public official for "high crimes and misdemeanors". In the federal government it is voted on by the House of Representatives. The impeachment itself has no significant consequence. It is then followed by a trial in the Senate. If convicted, the possible punishment is removal from office and disqualification from future office. A regular criminal process can then take place.
None of these aspects of the process is advisable right now in relation to the Benghazi, IRS, AP, EPA, or other scandals.
Right now we have no information to show that President Obama was directly involved in any of it. Investigations are still going on, and only Benghazi has had congressional hearings so far. It's way too early to start drawing up walking papers for the President. Doing so now makes it look like a political vendetta rather than an honest quest for the truth.
The House would vote on impeachment. Republicans control the House. It would probably pass, but with the narrative already in place for the last three years that Congress is engaged in little more than partisan bickering, an impeachment vote would be the massive constitutional cherry on top of the cake.
The Senate would hold the trial. Democrats control the Senate (until maybe 2015). It probably wouldn't even be initiated. So the impeachment vote in the House would be the end of it. It would accomplish nothing. Obama would still be President, Washington would be even more bitterly divided than it already is, and the public would be annoyed by the whole thing by the end.
Only two Presidents have been impeached in our history: Andrew Johnson and Bill Clinton. Even after openly lying under oath, the public didn't support impeaching Clinton at the time. The GOP-led House went ahead with it and voted 228-206 and 221-212 for two articles of impeachment (two others failed). The GOP-led Senate held the trial and voted 55-45 against and 50-50 on the two counts and acquitted him. President Clinton's approval rating never got below 53% after impeachment, and he left office at 66%.
I shudder to even mention it, as the thought is too horrifying for words, but there's one last reason not to impeach and remove President Obama. Two words: President Biden.