I was first taught to identify Pinus ponderosa by looking at the needle bundles: 3 needles. You can bend the bundle to form a 'Y.' Y is for yellow, as in yellow pine. Only trouble was, I found out later, that the Jeffrey Pine (Pinus jeffreyi) also has 3 needle bundles, and goes by the common name of "yellow pine" as well. (In the Sierra Nevada, the two species can hybridize so it is difficult to tell the two apart. Guide books noting that Ponderosa bark is orange brown while Jeffrey pine is reddish brown aren't so helpful) A botanist taught us a miltary style call and response that proved more useful in identification:
Ponderosa Pine has puzzle piece bark!
(Ponderosa Pine has puzzle piece bark!)
Pine cones are prickly and they're sharp!
(Pine cones are prickly and they're sharp!)
My students dutifully repeated the chant, but it didn't help them in identification, until I held up a pine cone, turned to one student, and said "Here, catch this," as I tossed it to him.

As soon as it hit his hands he instinctively let the cone drop. The spines that curl outward from the cone make catching it very unpleasant.

Seeds are small (7,000 to 23,000 in one pound) and are eaten by insects, mice, birds, chipmunks. Native peoples would use the inner bark as food and its resin as a medicinal salve for rheumatism, backaches, and dandruff.

Sources: Lawrence Hall of Science Summer Science Camp; University of California Cooperative Extension