In an earlier post to the Forums, Berta suggested Calibre:
“Calibre, e-book managment tool (for mac, linux and windows). Freeware. Take a look at it.”
( from Ebook Format For Texts? - Language Forum @ LingQ, 13 Jan 2010)
Calibre is the best thing that I know for doing what you are wanting to do. Hmmm. But looking at your question again, I see this is not what you are asking for. Well, I’ll let my comment stand, just in case you do not know about Calibre and think it might be useful to you.
Hi Debbie, Your question rises up some more questions 
Do you look for free content or would you pay for the content?
For what language (or languages) are you looking for?
If an ebook has no DRM on it, you can open it with a tool, for example calibre or another reader on your pc and simply copy and paste the text. If it has DRM you need add-ons or other tools that are not legal (never the less easy to find on the internet).
For German you can have a look on my ebook blog:
http://pocketbook.verasblogs.com/wichtige-und-interessante-links/
Debbie, I did some research and there seems to be one problem if you want to buy German ebooks. I found “Um eBooks auf thalia.de bestellen zu können, ist es notwendig, eine deutsche Rechnungsadresse anzugeben, da uns nur die Lizenzrechte für den Vertrieb innerhalb Deutschlands vorliegen. Der Download selbst kann danach selbstverständlich außerhalb Deutschlands vorgenommen wird, da beim Download keine Überprüfung der IP-Adresse erfolgt.”
That means that you have to have an invoice address in Germany because of the Copyright lizenze that the publisher has.
Amazon has the huge advantage that it is an international player on the market, but most of its ebooks have DRM. So you cannot legaly import theminto calibre and copy and paste the text. See my post above. But it works without problems with all the free books. Unfortunately Amazon don’t tell you if a text has DRM or not 
If you search for “DRM Removal” on the mobileread.com forum you can probably find answers.
At least a few Russian book vendors give a choice of formats in which to download purchases. Those that have come to my attention are kniga dot com, rumvi dot com, and litres dot ru, all of which generally offer .epub, .doc, .rtf, .mobi, and .pdf e-books. While I haven’t bought from Rumvi, I have taken my custom to the other two sites without running into any problems.
I don’t believe that registration is required at Kniga or LitRes, though setting up an account will allow for viewing of past purchases and online access to that digital content. A couple of points to note on LitRes are that they accept PayPal and that the promotional emails tend to arrive frequently if the wrong boxes are left checked.
You can find some “Tools” for Calibre online that remove DRM when you import the ebook into Calibre. I have been using this method for a while and find it very practical.
I have a Kindle copy of Jakob Wassermann: Der Fall Maurizius. I have previously been able to read other books in this format on Calibre and import the text into LingQ, but the DRM on this book doesn’t get removed when I add it to my Calibre library. I tried ‘buying’ a free book from A…z, but it didn’t open either. Any suggestions?