how exactly are these rankings made? I mean, how is it decided who no1 team is or no7?
and how is it decided which teams can go to a bowl?
is that because of ranking or geogroaphy?
you're question has an answer but not based on a viable solution
there are multiple polls/ranking systems but the primary poll which is recognized is the BCS poll. the other polls are the coaches poll and AP poll and one more poll (which i forgot the name of).
teams are ranked higher/lower based on wins/losses after a weekend of play. on top of that the strength of the opponent is also taken into consideration as well as your teams performance in the win. Also playing at home or an away game matters as well.
the most baffling thing is the side logic the voters use when ranking teams. a clear and obvious team that should be ranked #1 isn't always selected. there is bias on what region a school is in and as well as the usual media hype which is exponentially biased than in any other sport.
college football is a great sport and like all sports its about money. these schools get paid alot of money and the NCAA is at the top of that hustle. its better to matchup teams for the Championship game that will bring in large revenue than a team that obviously played all season to deserve a bid for the title.