Upcoming Lithuanian election!

The US has appointed a new Ambassador to Lithuania.  He needs to know quickly, in three short paragraphs, what's going to happen this weekend - (1) what are they electing? why is this important? (2) who are the main candidates, and who might win?  (3) when will we know the results?  

(please note that the questions are phrased as an uninformed American might ask them-- while you answer, you may need to teach them some basic information about Lithuania's political institutions).

Post your first draft; you may change your mind, revise, etc. as you wish, but please don't edit your first draft, just add a "reply" with your new & improved 3-paragraph intro to Lithuanian politics.