Keep your stargazing sights and new experiences logged in a journal. Watch Amateur Astronomy for Beginners - The Astronomical Journal.
A few suggestions on what to write:
1) Date and time (local time and universal time).
2) Weather and sky conditions (is it windy or cloudy? Light pollution level?).
3) Object observed.
4) Seeing conditions (is the image shimmering or steady?).
5) Object details.
6) Your impressions, emotions while observing the object.