Bardic Sources
While there are many medieval sources to be found on the web, I stongly emphasize checking out your local library.  While there are some obscure works online that you won't find in your local libary, you will be amazed what is there hiding in the stacks.  And for large collections like Shakespeare or Chaucer, it is MUCH easier to flip through the pages and scan the poems in the comfort of your favorite chair than to stare at the screen waiting for each one to download.  Trust me!  The internet isn't always the fastest way!

Links and Sources

Jefferson Parish Public Library Catalog http://www.jefferson.lib.la.us/jplpage.catalog.html
SCA Minstrels Homepage - http://www.pbm.com/~lindahl/minstrel.html - Info about the bardic arts, and many links to song and storytelling sources.
Codex Fabliauum - http://home.earthlink.net/~yevsha/SCA/codex.html - Primary sources for stories, organized by place and time period.  Mostly lists books, with a few online sources. A must-see for the serious storyteller.
Internet Medieval Sourcebook Medieval Literary Texts http://www.fordham.edu/halsall/sbook2.html#lit2 - Just what the title says, all online.

Specific Online Texts
Note: I specifically selected short texts, this is not a list of all online medieval stories I know of.

Arthurian Texts from the Camelot Project - http://www.lib.rochester.edu/camelot/mainmenu.htm - All Arthur, all the time.
Ballads Lyrics and Poems of Old France - ftp://uiarchive.cso.uiuc.edu/pub/etext/gutenberg/etext97/blpof10.txt
The Canterbury Tales - http://www.vt.edu/vt98/academics/books/chaucer/ChaucerIndex.html - In modern(ish) English.
The Decameron - http://www.brown.edu/Departments/Italian_Studies/dweb/dec_ov/dec_ov.html
Guillaume Marchaut http://www.medieval.org/emfaq/composers/machaut.html - Poem-songs of the French 14th century troubadour, in French.
Medieval Irish Poetry http://www.dnaco.net/~mobrien/irishptr/irepoems/index.html
The Robin Hood Project - http://www.lib.rochester.edu/camelot/rh/rhaumenu.htm
Shakespeare's Sonnets http://eng.hss.cmu.edu/poetry/sonnets/

Suggestions For Selecting a Bardic Piece