This question is getting answered a lot lately. It was asked yesterday...the title is something about importing Amazon books. Answers in there (on how to import).
Public posting of copyrighted material is forbidden. Yes, you might see a few that have eluded being reported and removed, but none-the-less that is the law and the rule.
Importing a novel you own privately to your own account requires a DRM-free copy of the ebook (an ebook without Digital Rights Management / copy protection) in one of the following formats:
EPUB, PDF, DOCX, TXT, MOBI, SRT, ASS, VTT, TTML
Kindle ebooks have DRM which would need to be removed. This is typically done using the Calibre ebook library manager and the noDRM plugin. Search these forums or those at MobileReads.com for more information regarding these tools.
On kindle most books are protected with DRM. If you want to import a book in LINGQ, you must have a DRM-free copy. There must be ways to remove DRM from a book on kindle, but I think it is difficult.