Fresh paint, new counters, new cabinets, and appliances all add value. However, use care in renovating strictly for the purpose of selling. Give careful consideration to what will quickly enhance appearance. New wallpaper or paint will help without a large investment. New paint and hardware can give tired or dated cabinets a fresher look.
Bathrooms are also critical.
Make sure they are kept clean. In poor condition, they detract heavily and can impact the sale price even more than the cost of repair. As with any improvement, select renovations carefully. If you do, you'll either have to ask too much to be competitive, or lose some of the money, you had hoped your investment in renovations would gain. Light neutral colors appeal most to buyers.