From the official steamworks FAQ on 2k's Civ V forums:
Q. How will Steam know that I bought a boxed copy of the game?
A. The box contains a product code that you use to register your purchase to your Steam account. The box also contains a disc that contains the data files for the entire game. When you install from this disc, it will install Steam if necessary and then place all of the game files on to your hard drive, negating the need to download the game from the Internet.
So even though you don't have a DVD drive, you shouldn't have a problem installing Civ V, as as soon as you register via steam, you can simply download the game through steam.