Yep - sunscreen is a must! As far as chemical ones go, Anthelios is a good one... I'm just more of a fan of the mineral ones (zinc oxide / titanium dioxide). They're also better for sensitive/breakout-prone skin.

For acne - have you seen my cod liver oil post? Read the testimonials - it's AMAZING. http://beautyeditor.ca/2010/09/02/the-single-best-product-evah-for-your-skin-is-not-in-fact-an-actual-skincare-product/