We recommend an SPF 15 (Sun Protection Factor) or higher (SPF 30 or higher if you are going to be outdoors all day).
Use it daily! 80% of all skin cancers occur on the head and neck, mostly from the day-to-day sun exposure we don’t really think about.
-Put it on in the morning after you brush your teeth or shave. 
-Don’t forget the backs of your hands and forearms or your upper chest if those areas are exposed.
-If you have short hair, be sure not to miss your ears or neck.
-Consider a lip block (many types of “ChapStick” have sunscreen.)

Waterproof sunscreens will be a better choice for you if you are likely to be perspiring or swimming. No one wants to have sunscreen run into his eyes, so if you’re going to be running or gardening look for “waterproof” or “water resistant” on the label.
Good waterproof sunscreens:
Coppertone sport
Neutrogena oil free
Pre-Sun or Pre-Sun Ultra
Bullfrog
Neutrogena UVA/UVB block
Ombrelle
Bio Sun

Moisturizers often have sunscreens “built in” If you already use a moisturizer in the morning, just be sure to choose a product that has a sunscreen in it. 
Good moisturizers with sunscreen:
Oil of Olay (look for the UV protection version)
Cetaphil
Neutrogena or Neutrogena Healthy Skin
Purpose
Eucerin daily protective lotion

Parsol is a newer sunscreen agent that blocks a broader spectrum of ultraviolet rays. It is particularly helpful if you are very fair skinned, outdoors a lot, or if you want to minimize the aging effects of sunlight. The italicized sunscreens have Parsol (look for it on the label).

These are just some of the many excellent brands available. The most important idea is that you use sunscreen regularly.