For example I know combat prayer will give everyone Minor Berserk, Resolve and Ward. I think one nightblade used Piercing Mark for Major Fracture and Major Breach? What other buffs and debuffs are generally used?
You mean what buffs are provided to the team or just self buffs? Because that's a huge list..
But for team buffs.. the most common (healer point of view) Spell power cure, Worm Cult set buff, Mending set buff, Minor intellect and the hp recovery one, Shards(or blue balls), and elemental drain just to name a few really.
The availability and uptime of each varies based on the specific group/guild you are with. If it's not a steady group the only ones I count on are major fracture, major breach [both of which should be applied by the tank as part of their taunt], and minor magickasteal which most magic based DPS count on.