Classifying carbs as good or bad is kind of black and white but generally speaking, you want to base your diet around whole, unprocessed single ingredient foods. They will provide the most nutrients and raise blood sugar the slowest.
Some of my favourite low GI carb sources include sweet potato, brown rice, oatmeal and quinoa.
Generally speaking, if it comes in a box and has over 5 ingredients, you shouldn't be eating it.