Brakes?

My truck started out shaking when braking. Now a year later it shakes when driving at high speed, braking and i've heard a brake grabbing occassionally and there a turning sound from the tire like the brake is always slightly engaged. I doubt it's the front end going bad as it was all replaced at the dealers less than three years ago but what to ask opinions to make sure. Do you think it's just the rotors and brakes (brakes have been replaced twice in last two years after brother put first set on wrong and they jacked up but I didn't replace rotors or have them turned like I should have) and should I just be extra safe after waiting too long to fix this and just replace rotors instead of having them turned?