I would recommend you start with the Wood Pin Brush. The large, rounded wooden pins feel like a massage against the dog's skin. These large round pins also don't pull at the hair and the brush is very forgiving in the hands of an inexperienced groomer. Your dog will LOVE being brushed with this tool, so they will trust you when you need to bring out the more serious brushes.
You will also need our Ice on Ice Detangling and Brushing Spray to condition the hair so it doesn't break while you brush. The spray will also add some slip to the hair to help detangle and demat the hair. These two items will be part of your daily brushing regime.
They won't get rid of all the mats and tangles (you will need a slicker brush for that), but they will get rid of a lot of them and they will keep the hair from getting unruly between format grooms.
If the dog's hair is thick and you are looking to keep it longer than 1.5", you might want to consider the Ice Slip Dematting Brush instead of the Wood Pin Brush. The pins are longer so it will get deeper into the coat.
Wood Pin Brushes come in Small ($36), Oblong ($40) and Large ($46)Ice Slip Brush ($42)
Ice on Ice Detangling and Brushing Spray - Ready To Use ($19)
Ice on Ice Detangling and Brushing Spray - 15:1 Concentrate ($53)