Your level from Mass Effect 2 will carry over to Mass Effect 3.
Your Squad Members will also start at the same level.
You will get Squad Points to upgrade your Powers based on your imported level. If you import a Level 30 Shepard, you will have 1 point automatically placed for you in one Power, and 59 available to place at your whim.
Your Paragon/Renegade points will bump your Mass Effect 3 Reputation meter up about one quarter. Your Morality choices will be reflected.
7 Easter Eggs
Metal Gear Solid Reference
Submitted by NobleLeader6
Import a file from Mass Effect 2 where Grunt survived the suicide mission. Now you can get a message from him after either saving or condemning the Rachni Quenn on Utukke. At the end of that message, Grunt will type "SHEPERD S HEPAURD SHEPARUD", which is a reference to the message that appears when you die in Metal Gear Solid.