Having a display of your weight loss is so good for your mental attitude, that the mental boost it gives you to see your weight reducing is immense.
One of the toughest things about weight loss is being able to see how you are doing and being able to adjust your eating lifestyle to match your progress with the graph.
One question that we debated was whether to weigh everyday or once a week.
I don't really have a answer for that although I have a solid preference for weighing daily (morning).
My reasons for this is to make sure that I do not gain to much over a few days period. Each day is not always a weight loss day. Some days you can gain a little, but if you weigh daily you can adjust quickly if you see a steady gain.
To see yourself losing ounces or sometimes a pound or so over a few days weighing is a huge boost and it really encourages you to try harder.
So my suggestion is to weigh daily and keep the motivation going.