For most better jazz artists, especially those whose majority of work was in the 1950s and 60s, it's really hard to pick up a completely bad album.
Also, be aware that many jazz artists, even within the same time period sound completely different, using different players and different instrument set ups even within one's own career.
Year is a partially good indicator of what type of jazz is being put forth by an artist, but knowledge of an artist helps too.
Guys like Miles Davis were all over the place, from 'cool jazz', not to be confused with smooth jazz, with I tend to classify as any cookie-cutter jazz that has no real heart, skill, or any real progression of the music itself. He did 'modal jazz', which I've felt is the most beautiful if executed correctly and with taste. He even did 'fusion', which, with a few exceptions, is probably the most commerical, slick, overly-produced, and most important, boring type of jazz there is. Please stay away from this unless you really do your homework on what is good in the genre, i.e. Weather Report... that's it. He also did many others, and so did most other jazz artists, with a few exceptions (Art Blakey). But this also doesn't mean that just because they didn't 'progress' with jazz that their later stuff was any less good or interesting.
Other significant artists:
John Coltrane, Sonny Rollins, Andrew Hill, Chick Corea (before he became all commerical), Bill Evans, Dave Holland (or anyone else from the ECM label, for that matter), Joe Henderson, Art Blakey, Horace Silver, Ornette Coleman, Cecil Taylor, McCoy Tyner, Pharaoh Sanders, Art Ensemble of Chicago (early stuff only), Donald Byrd, Herbie Hancock, Dave Brubeck, and many others.
Good resources:
MurraytheCat on Amazon.com, look for his profile, he has an incredible knowledge of jazz and has extremely good taste when it comes to his selections of good jazz.
www.allmusic.com, also a good site, that I've noticed, hardly gets it wrong when reviewing a jazz or classical album. (They're kinda iffy on rock/other stuff)
One last thing, be careful of most jazz albums released after about 1975, as for older artists they just start to re-hash older stuff without much of their old flair, or it tends to be overly electronic or slick, it loses much of what I feel made jazz great. Still, there are plenty of good albums, especially by resident artists of ECM.