If anyone here is even vaguely curious about jazz, but didn't know where to start, Jazz Heritage has an offer where you get 4 CDs for 99¢ with no obligation to buy more ever. After shipping, that's only $13.82 total. They only have 14 CDs available for this offer, but they're some very good ones. Miles Davis's Kind of Blue is almost universally considered the single must have jazz album for good reason. I like their Cannonball Adderley and Duke Ellington albums, but it'll depend on what kind jazz you think you'd like. The Jazz for... collections are quite good, especially Jazz for the Open Road.
Of course, i also strongly recommend people listen to my very favorite active band, and the one that got me started on jazz, The Living Daylights. They're a funky jazz-fusion outfit, which may be a more accessible starting point for the musically curious. If you love me, you'll try listening to some of their downloads.