During my high school years, the local public library was one of the resources I would use to hear jazz recordings. One I vividly remember was the Smithsonian Collection of Classic Jazz. It was a multi-record set that included items from Scott Joplin, Duke Ellington, Charlie Parker, etc.
Last week, a new edition was released. It's six CDs and 111 tracks! (I think the original was 8 LPs.) It's been updated to reflect the changes that have occurred since its original 1973 release. But all the great classics (West End Blues, Hawk's Body and Soul, Duke's Ko-Ko) are still there. It would be a great investment to fill in those gaps in your jazz knowledge or collection.
As a taste, there's a link to a Mary Lou Williams recorded of Virgo, part of her Zodiac Suite. By coincidence, that happens to be my sign: http://soundcloud.com/smithsonian-folkways/virgo-mary-lou-williams-jazz
And if you're feeling brave, take their jazz quiz while you're there: http://www.sporcle.com/games/Smithsonian_Folk/JazzChallenge25