My little one now has 4 teeth. Should I start brushing? Any recommendations on toothbrush and toothpaste brands?

You can consider Earth's Best Toothpaste for children. It is suitable for children from six months to three years. It's fluoride free, so safe to swallow for children who are unable to spit. There are available on iHerb and there are two flavours to choose from. http://sg.iherb.com/Kids-and-Baby-Toothpaste#p=1&bids=EAB