A quick search (kdenlive doc / k forum / giant internet) give me :

http://userbase.kde.org/Kdenlive/Manual/Capturing
http://www.kdenlive.org/forum/audio-microphone
http://opensource.com/life/11/12/kdenlive-part-5-all-about-audio
http://www.kdenlive.org/mantis/view.php?id=2841

hope it's help //// if you found whay you are looking for from those links, be free to share in the forum.

see(:ya!