The next issue is to select good toothpaste. In general, any toothpaste that contains Fluoride will do the job, unless you have special needs that are determined by your dentist. Two of the best brands of toothpastes are Colgate Total and Crest Multicare.
The first rule of brushing is to start from a specific location and work your way to the opposite side, continuing all the way through the whole mouth so that you end where you started. This way you won't miss any area. Usually a pea-sized amount of toothpaste is enough. An adequate brushing should at least take 2 minutes and preferably around 4 minutes.