Joan,
As Tim, Guy and others have pointed out, capturing RAW provides the most any camera capable of delivering that kind of file will produce, and give you the most flexibility. However, there are some things that one can do when shooting JPEGs that can have them coming out of the camera looking quite stunning. First, make sure your white balance is correct for the scene you are shooting, and if you can custom white balance, that is the best way to go. It will require doing that for each new lighting setting, but it is so worth the effort. The second thing is to make sure your exposure reading are as good as you can get them....not blowing the highlights, nor clipping/crushing the blacks. Sometimes a 1/3 stop either way can make a world of difference in the final product. Always save the largest (least compressed) JPEG file you possibly can. Memory cards are cheap, and more data saved is better every time. And play around with the camera settings to get your contrast, sharpness and saturation to your liking, and maybe even different for different settings/scenes. If you start doing these things regularly, you will be amazed at how easy shifting to RAW will become, as you are essentially setting things up for as good a capture as you can from the start. After that, playing with RAW files in processing can become both fun and creative.
So, if you have a camera that allows the kind of adjustments discussed, you can crank out superb JPEGs. Many event photogs and others taking high volumes of shots never bother with RAW, but they do bother getting the settings as best they can for JPEGs. That learning process actually makes RAW look easier after a while, and once you shift, you will not want to go back.
LJ