The best information source in english about World Masterpiece Theater (that includes 3000 Miles in Search of Mother) is Benjamin Ettinger's site
Sub Rosa - Rare and Literary Anime
On the site, click on DB
and you'll see a list of World Masterpiece Theater series. Select a series and you'll se information about it.
BTW, Benjamin Ettinger is the man that translated the entire Romeo's Blue Skies series for Technogirls (the only WMT ever fully subbed in english).
People in European countries are much more familiar with WMT, as many series were broadcasted there. Some series were also shown in Latin American countries. Some series can be found on DVD in Europe, usually only dubbed unfortunately. One that was recently released with a Japanese sound track and subs is the last WMT series ever made: Homeless Girl Hemi. It's being released in Italy right now as
Remy - La Bambina Senza Famiglia
They're usually very, very good. I wish more of them would get more fansubs. Another WMT that got some episodes (16 to be exact) on tape were Tico and Nanami (or Tico of the 7 Seas) that was fansubbed by the Neko Creations (the fansub group that originally did the Yawara fansubs whose scripts Live Evil is using). Maybe Live Evil could be the same thing (fansub it based on the Neko scripts) as those scripts also seen to be available for download.
3000 Miles in Search of Mother:
Romeo's Blue Skies:
Little Princess Sara
Heidi, Girl of the Alps
Homeless Girl Remi (Ie naki ko Remi/Remi the Homeless Girl/ Nobody's girl)
Katri, Girl of the Meadows
Anne of Green Gables
Daddy Long Legs
Tico and Nanami
as I don't like the Tico and Nanami DVD covers, here is a CD cover that gives a better image of the show actual visual
There are others, of course.