personally i use bandicam which is great; lets you record 2 audio sources at once (mic and game sounds for example, with the option to only record the 2nd via holding a key down), exclusive full screen or custom window sizes, doesnt use much system resources, allows webcam pretty much anywhere and any size.
its not free however there is a trial version (i think bandicam is well worth the money though if you're looking to record more than just a video or 2)
https://www.bandicam.com/free-screen-recorder/
if you want to edit your video then use something like virtualdub or another video editor (virtualdub is free and very powerful but can look a bit confusing at first)
http://www.virtualdub.org/
p.s. record in bandicam in avi format as virtualdub handles that much better than it does mp4.
once you're done you can simply upload the video to youtube or some other video hosting site and then link it here.
