Good Advice. I'll add, based on my dark past (I came to cycling as a recovering basketball addict with horrific knee issues-short people shouldn't dunk.):

6. Raise your rpm. Two things here: higher rpm lowers the peak stress on the joints and also forces you to clean up your pedal stroke. If you are bouncing all over the place, then you aren't pedaling circles. Target a cadence of at least 95 rpm and force yourself to do lots of miles with it over 110. It's uncomfortable at first, but the payoff in terms of better pedaling technique is worth it.

7. When the knees are healthy, consider adding leg extensions and leg curls to your regular workout regimen. I'm not sure why, but the strength gained through these exercises seems to help keep the knee stable and healthy. Do one leg at a time, fifteen reps per leg per set, no rest between sets, five to ten sets of extensions before changing out to curls. Repeat, adding weight as desired (start too low).

8. Keep you legs warm while riding. There isn't much insulation around the knee, so you need to cover it to keep it warm while riding.