Sure, there are those people who buy next year's wrapping paper on Dec. 26 and finish their holiday shopping by August. But assuming the world is skewed a bit more toward us than them, we offer up this delectable guide to the newest and coolest and warmest of entertainments available for the holidays. There's a rundown of music boxed sets from groovy to nostalgic that will please everyone, including that nephew who just pierced his ear and says, ''Hey, dude,'' and your aunt who swoons to the Everly Brothers. Our multimedia section guides you tenderly through the world of video games and CD-ROMs, and we'll let you know how recent video releases will fare under the tree. And when you're done perusing the lush books we recommend, you can tear out our movie guide and take a break from all that eggnog at your nearest cineplex. From head to stocking, we've got you covered.