So a lot of people ask why triangular polygons are bad when poly modelling.
It's not that they're bad it's that they don't work well when using Dynamic Subdivisions like we do in a lot of modern modelling applications.
Since I haven't seen anyone explain it better here's a link to guerrillacg.org's explanation pt.1;
Clickety Click!Guerilla CG is another great place for general and basic 3D topics if you're in the mood to learn.
