Saving question

Okay, lately I've been noticing that the clarity of my icons is pretty much stuck down in the crap-hole. My text is blurry, previously crisp images are slightly distorted. This isn't a new thing, it's been happening, but before now I just didn't care. How can I tell PSP to save my .jpgs with better quality? Or am I better off using something like .png? I personally don't know a lot about that format. And the memories I looked at couldn't give me a clear comparison between .jpg and .png.

Any help you could give would be greatly appreciated.

(crossposted to psp8_fun)