Youtube video maker - Screen Recorded Content

I am planning to start new youtube channel with some guides . It will contain some power point presentation with voice. i have downloaded some screen recorder already.
now i need to edit vidoes, to remove noise and change sound quality.Can you please recomend me good software.

as i am starter it is great if it is freeware or some crack so that i can get it free. i will buy it later

audacity is just what you need for editing audio clips I believe.

Camtasia for tutorial
Proshow gold for slideshow
Wondershare filmora for all round editing