Data - Art Duration : this is the duration of the "eye candy".
Data - Base Order Id : channel is the only spell with the option to change it's id. This options allows the same unit to have multiple spells based on channel. You just have to change the id.
Data - Disable Other Abilities : just like Bladestorm. It disables the unit's command buttons.
Data - Follow through time : the duration of the channeling. Note : if you set it to 0 it will channel forever. So if you don't want channeling set it to 0.01 .
Data - Options : There are several fields here. What you need to know is :
Visible : The channel icon is usually invisible but if you turn this option on, it can be seen.
Physical Cast : this means will the spell be counted as a normal spell, or a physical one(ensare for example). If counted as physical it can target spell immunes.
Data - Target Type : Will the spell be instant(like manashield), unit targetable(like stormbolt), point targetable(like blink) and "unit or point" targetable(like shockwave).
Data - Area of Effect : if the channel is point or "unit or point" targetable, you can adjust its area of effect with this.