Just as with iTunes, where you can rate your favorite songs on a scale of 1 to 5 stars, you can rate your photos, which is a great way to identify your favorites easily.
Ways to assign ratings:
Select one or more photos, and from the hierarchical My Rating menu in the Photos menu, choose the desired rating. Note the through keyboard shortcutsif you're ever going to use keyboard shortcuts, now is the time.
Select one or more photos, -click one of the selected photos, and choose the desired rating from the hierarchical My Rating menu (Figure 3.43).
Figure 3.43. To assign a rating to a photo, Control-click the photo and choose the desired rating from the My Rating menu (or use the keyboard shortcuts, which are a lot faster in this situation). Here you can see my star ratings underneath the photos.
With a photo selected, click the appropriate star button in the Information pane.
With the slideshow controls turned on, click the star buttons to assign ratings while the slideshow runs.
After you choose a rating, iPhoto applies it to the selected photos, displaying it below each photo if you have My Rating () turned on in the View menu.
The keyboard shortcuts for rating photos are available at all times, even when you're playing a slideshow!
You can change the rating for a photo at any time; it's by no means set in stone.
iPhoto considers 5 stars better than 1 star, although there's nothing stopping you from assuming the reverse.
Consider Using Only High Ratings
Don't assume you must rate all your photos. My feeling is that there's relatively little point in rating anything with 1 or 2 stars, since those ratings basically mean, "I like this photo only enough to keep it." I consider 3 stars an average rating, so I usually don't use that either, reserving my rating effort for the 4- and 5-star photos that are my favorites.
Remember too that you can create smart albums that match photos whose ratings are lower than a set number, so you could easily find all the photos that didn't have 4 or 5 stars.