Mildew is a fungus that grows in areas that are hot and moist, so extremely humid conditions are perfect places for the mildew to grow. Mildew removal is fairly easy if it is only a small area you need to remove it from, for larger areas it may take a little while longer and the process for mildew removal may also vary depending on the surface it is on. The other part of removing mildew is getting rid of that musty scent that mildew has. Mildew will grow in all kinds of places and the walls in your kitchen and bathroom are the most susceptible to this as well as the countertops, sinks, and showers. One of the best ways to clean it off of these areas is with a mixture of water and bleach, and when cleaning mildew off of paint you may want to use an even weaker solution of water and bleach, this will avoid damaging any paint.
A great way to avoid having to deal with mildew removal is by taking the precautions to try and avoid the mildew fungus from growing in the first place. A couple precautions you can take are to be sure the rooms like the kitchen and bathroom have good ventilation systems to help eliminate some of the hot moist air. This is especially important in the bathroom where you take hot showers, since that will build up a lot of moisture on the ceilings and walls, which will then turn into mildew. These are some of the most common places to have to perform a mildew removal job on, and with good ventilation this could be avoided altogether. Another thing to remember is that when you are painting you cannot just paint over mildew, it needs to be cleaned first with the mixture of water and bleach and then a touch of primer would be good as well before the paint. If you were to just try and paint over the mildew it will just grow right through the paint.