Here you find a series of screencasts (video tutorials), ranging from beginners stuff to more advanced tasks.
How to mount network drives / NAS storage with samba-mounter:
How to change the wallpaper:
How to add a menu icon to the panel:
How to backup a video from the internet for offline viewing:
How to add searchfield to Firefox searchbar:
Check CPU and memory consumption of running programs and force-quit a program