Which exercises should i avoid in early hip osteoarthritis?

Avoid high impact: Mild arthritis in the hip should be exercised, but one should avoid high impact exercise. Instead, one should do low impact exercises such as swimming, cycling, elliptical trainer, stair master, and stretching. Discuss the specifics with your doctor.

High impact: Avoid high impact exercise such as running & jumping. Stick with low impact such as swimming, biking, and elliptical use.

Hip Muscles: Strengthen all the muscles around the hip joint, including the back/thigh muscles. If you are unsure, I would suggest getting an evaluation by a sports medicine trained physical therapist.

Heavy weights: I would advise against heavy squats and deadlifts, for example, which would put a tremendous strain on the weakened hips. Lighter leg presses and leg extensions could be helpful, as could very light work on the abductor/adductor machine - high reps, light weight, build the muscles around the hips.