Navigate to 'Goals' in your sidebar and choose the goal you wish to update by clicking on it.
By scrolling in your goal view you will see the following options:
In the progress made text box you can provide an update against any progress you have made. Next you'll be ask to select whether you view your progress as Off Track, Progressing or On Track by clicking the relevant option.
Finally, under key results you can select which key result you are entering progress for by clicking the arrow next to the key results and entering the current value for your progress vs your goal value.
When you are finished entering your goal progress be sure to click the button entitled 'Update Progress' in the bottom right corner as shown above.
If you don't click 'Update Progress' your progress will not be saved.
Finally, if you scroll to the bottom of the page you will find a timeline of progress updates and comments as shown below:
Here you can leave a comment on any updates and thoughts you have on your goal.
To leave a comment click above the line and simply type your comment. When you are done click enter on your keyboard. Here you can also see any comments you have left in the past.
If you don't click enter your comment will not be saved.