You need to balance your wheels. Sometimes, your shocks can worsen the experience.
Steering wheel shakes
Warped rotors
allignment
could be bad alignment
usually steering shakes over 60 mph is due to front tires needing to be balanced unless you have something more serious going on.
I have seen this with bad or unbalanced tires.
Tires out of balance, bent wheel, tire defect, or suspension or steering parts worn.
it shakes to the right or left
You probably have rusty/scored brake rotors.
Wheels are likely out of balance
You need an alignment.
depends on when it shakes if it shakes when you put on the brakes-warped rotors otherwise it could be ball joints, steering joints, wheel bearings or even out of balance tires