Once you've got the teams you'd need to draw out a playoff bracket with the teams seeded. Example say Georgia Southern and Old Dominion played in the first round you'd play the game in 'Play Now' and then you'd play the next set of brackets which may be Appalachian State and Maine so you'd play that game in 'Play Now' and then the winner would play Georgia Southern in the next round. Just like a real playoff bracket. The one for this past season for the FCS can be found here,
http://www.ncaa.com/interactive-bracket/football/fcs