Avatars are for full members and up, meaning 120 activity, meaning you need to be active on the forums (aka: 1 post/day) for 120 days or 18 weeks or 4.15 months. Then you go to your profile settings and upload up to an 80x120 picture.
Yes even i can not upload avatar yet in my profile right now as i am only as member and that option is not available in my profile yet.
I am about to become full member in next couple of days,so excited about that to see,avatar adding link/option in my profile settings.