It's not settled opinion, but it is settled science. See:
Introduction to strength training for the endurance athlete
for more opinions and workouts.
Then see:
Incorporating Weight Lifting into Training
for the scientific papers.

The important takeaways are
#1 don't get injured! Meaning you have to have good form and work up to it. This takes time and education.
#2 you get results by lifting heavy and using the appropriate range of motion, see the papers above. If you're doing it right as a road cyclist, you won't put on much muscle mass, just get stronger and have better endurance.