If you don't like the movie, I wouldn't recommend getting the soundtrack, unless you like darker, edgy 90's music.
If you do like it though, like I do, then you should get this along with Graeme Revell's score (which is beautiful. Please see my review for that).
The soundtrack is not chronological, where the songs play as they were in the movie, but that isn't the problem with it. The only problem I had with it was that it wasn't long enough! The Craft is one of my favorite movies, so naturally, I love the soundtrack (especially Love Spit Love's cover of "How Soon is Now?" which went on to be the theme song for Charmed). There isn't one "light & fluffy" song on the album, which is what gives it that darker, teenage-angsty feel to it, which is what the movie really had going for it. Even Jewel's song "Under the Water" isn't a typical Jewel song - its a bit darker, which made it perfect for the movie.
If you're still unsure about getting the score, listen to track 13 - "Bells, Books & Candles" by Graeme Revell. This track isn't on the score album, but gives you a taste of what it is all about.
Overall, a great soundtrack to a great movie.