JPG vs RAW and Color Space
When ever possible, all quality photography should be taken in RAW format with ProPhoto RGB Color Space.
However, RAW is not a convenient format and therefore not popular on the consumer level of photography. Most cameras will produce high resolution JPG images designed to be outputted onto the web using the lowest quality "sRGB" color space.
With that said, if your web site will be needing photography updating over a period of time, then you should look into photographing and producing images from RAW format. The advantages are that profound and open up a huge advantage for image manipulation.
Color Space
Color Space can get technical very quickly. But for the purpose of this discussion we will keep it very basic.
Have you ever seen a photo in a program like Photoshop which looked so good only to notice how bad it was on the web? The problem was probably color space.
Back in the stone ages of the early internet we saw "sRGB" color space. For its time, it worked well and gave us as good of image quality our older computers could give us. But soon, the computer equipment out grew "sRGB" so in 1998, Adobe introduced a new color space called "Adobe RGB" or "a1998". It caught up color management to the technology level of the equipment. Recently, Adobe rolled out the current "ProPhoto RGB" color space to keep up with not only the computer equipment technology but the digital camera technology and RAW file format.
So what to do?
As of now on this changing subject of color space, start with Pro and output to intended use. For example, photograph in Pro, do your enhancement then convert to "s" for web site use. Do NOT put a "pro" color space on the web with out converting to "s", you will not like the result. Your site users will probably not know whey they don't like the image, but they will not carry away a positive impression of you and your web site.