The target for the Dolphins is Miami RB Lamar Miller, who is the best player still on the board, according to SB Nation's NFL Draft blog, Mocking The Draft. Miller was considered a 2nd round value by some so this is a solid pick.
The Dolphins had good production from Reggie Bush last year so they hope Miller can come in and do the same. The Dolphins selected Ryan Tannehill and Jonathan Martin with their first two picks. It's been a productive draft for them so far.
Results from the 1st round of the 2012 NFL Draft can be found here, 2nd round results are available here, and 3rd round results can be found here. For more player rankings and draft information, check out Mocking the Draft.