Kissing scenes can either scream "hot", or "not so hot", depending on how your write them. What you need is the right kind of kiss to send your scene over the edge. Or maybe you're looking for a more quaint kiss that will just be a bit romantic.
First off you need to give details, but don't be too crude about the way you put them. Unless you're writing an x-rated story than go for all the detail you want and need. But a good normal kissing scene doesn't need x-rated material to make it hot.
The way that the couple look at each other before they begin to kiss can say a lot. Her head tilts a bit and she gets a look that is almost far off to her. He has the look of a caged tiger about to escape it's prison as he leans into her slightly.
Even examples of how they smell leading up to the kissing scene and in it are essential to create the perfect setting. Not something like she smelled good, but much more descriptive. Her skin smelled of roses that were freshly picked for a bouquet.
It's all about the way you word and describe the scene. However, you need to make sure that you don't stick to the cliches either. The phrases that are used way too often, will make the scene a normal kissing scene. Make it your own by adding so much more. Now onto describing the kiss.
The kiss itself should be just a simple stating of their lips met. That's way too boring and not near enough attention is placed to making people feel the power of the kiss. Trying something more along the lines of "The lips of the lovers met, like an embrace that was long lost." May sound a bit cheesy, but I don't want to give away too many secrets. Be creative in your descriptions!