Welcome to MobileRead, memnochskat!
I don't have a Kindle, but I definitely make sure any purse I buy is big enough for my Sony!
Because lit files are protected with DRM and it is illegal to strip the DRM here in the US, we can't really tell you how to do it. Having said that, if you use your search engine and ask how to convert lit files, I am sure you will find the information you seek.
As far as pdf files on the Kindle, I'm afraid I can't help. But if you check out the Kindle forum, I know we have plenty of gurus there who can help.
From one "Crafty" person to another, welcome!!
Happy reading.