http://www.star-k.org/cons-keep.htm

The symbols on the Va'ad list are all widely-accepted kosher certifications commonly found on products throughout the United States. With a little practice, it is very easy to spot these marks on food labels, usually near the product name, occasionally near the list of ingredients. There are many other certifications available, of varying degrees of strictness.

The most controversial certification is the K, a plain letter K found on products asserted to be kosher. All other kosher certification marks are trademarked and cannot be used without the permission of the certifying organization. The certifying organization stands behind the kashrut of the product. But you cannot trademark a letter of the alphabet, so any manufacturer can put a K on a product. For example, Jell-O brand gelatin puts a K on its product, even though every reliable Orthodox authority agrees that Jell-O is not kosher.

It is becoming increasingly common for kosher certifying organizations to indicate whether the product is fleishig, milchig or pareve. If the product is dairy, it will frequently have a D or the word Dairy next to the kashrut symbol. If it is meat, the word Meat or an M may appear near the symbol. If it is pareve, the word Pareve (or Parev) may appear near the symbol (Not a P! That means kosher for Passover!). If no such clarification appears, you should read the ingredient list carefully to determine whether the product is meat, dairy or pareve.

List of Va'ad Approved Kosher Symbols