There are two main varieties: flat-leaf and curly ('Savoy'). The flat-leaf kind can be broad and round, or pointed; the young leaves (baby spinach) are tender and delicate.
In Season: Fresh spinach is available year-round.
What to Look For: Look for bright green, unwilted leaves. Avoid slimy or spotted leaves.
How to Store: Once at home, wrap spinach in paper towels and store in a plastic bag in your refrigerator's crisper. Whether prebagged or home-bagged, spinach should last about three to four days.