A disc that doesn't appear in the Finder after you burn it is probably OK if no alerts appeared while it was being burned. Simply eject the disc and reinsert it to make it appear in the Finder. You only need to do this one time after burning the disc. Eject the disc by pressing the Media Eject key or the F12 key.
Update to Mac OS X 10.3.4 or later to avoid this issue.
Tip: You can burn CD-R, CD-RW, and DVD-R discs depending on your computer's disc drive.
If the disc still doesn't appear, see technical document 25545, "
Mac OS X: When You Put in a Blank CD, It Doesn't Appear".