There have been quite a few threads on this subject over the last few months and a search on "mp3" or "iPod" will probably find most of them for you.
While it's true that either uncompressed files, played from the CD or ripped that way to a hard drive, or files saved in a lossless format will sound better, your mp3's may sound fine, depending on how you ripped them.
iTunes will let you rip mp3's at anything from 16 kbps to 320 kbps. At 192 kbps or above, mp3's can sound pretty good to me, at the more typical lower rates they can be not so great. Whether the sound is acceptable depends on many factors including the quality of the original, the resolution of your system and, most important, your own standards.
There's no reason to be too concerned about it, though, just try it and listen. It may be that you can't hear enough difference to go to the trouble of re-ripping or playing from CD. It's also possible that it's worth it only for a few albums. I ripped three or four hundred CD's to Apple Lossless format, even after I had at least have of them as 192 kbps mp3's. I'm not exactly sure it was worth it but I figured I'd only have to do it once and it's really not all that much work.
While it's true that either uncompressed files, played from the CD or ripped that way to a hard drive, or files saved in a lossless format will sound better, your mp3's may sound fine, depending on how you ripped them.
iTunes will let you rip mp3's at anything from 16 kbps to 320 kbps. At 192 kbps or above, mp3's can sound pretty good to me, at the more typical lower rates they can be not so great. Whether the sound is acceptable depends on many factors including the quality of the original, the resolution of your system and, most important, your own standards.
There's no reason to be too concerned about it, though, just try it and listen. It may be that you can't hear enough difference to go to the trouble of re-ripping or playing from CD. It's also possible that it's worth it only for a few albums. I ripped three or four hundred CD's to Apple Lossless format, even after I had at least have of them as 192 kbps mp3's. I'm not exactly sure it was worth it but I figured I'd only have to do it once and it's really not all that much work.