CRJ200 Captain reports the terminology in an abnormal checklist procedure for a PITOT HEAT failure is confusing and may result in inappropriate actions on the part of the user.

Narrative

On initial climbout we incurred a failure of the entire left side electrical anti-ice protection system. Messages were L PITOT HEAT; L AOA HEAT; L STATIC HEAT; PITOT BASE HEAT. As the L PITOT HEAT was the first message to be displayed; we ran that checklist first. The checklist states to recycle the left pitot heat which we did to no avail. The next step was to; in the words of the checklist; 'Select the Air Data Computer (ADC) Source Selector to the operating side.' First; this is confusing as it implies selecting the ADC Source Selector to the side with the operating ADC (of course both were working at this time). While we quickly understood the correct meaning; a better phrase would have been. 'Select the ADC Source Selector to the side with the operating anti-ice system.' Secondly; the ADC knob is not labeled 'ADC' - it's labeled 'Air Data'. Making the checklist match the knob label; or; clearly specifying 'the knob labeled 'Air Data' would be less confusing. Next; when we selected the air data source to the working side; it knocked the mach trim off line. We could not get it re-engaged. (Later; at the gate; we re-selected the selector to its normal position and discovered we could now engage the mach trim- thus this checklist action caused the problem with the mach trim). The checklist makes no mention that this action will disable the mach trim - its needs to be in there. Additionally; we discovered that I could not set the airspeeds; barometric setting nor could I engage the autopilot from my side. While given some time to think about our systems knowledge after the checklist had been completed; this made sense as we recalled our systems training. However; I feel this information should also have been included in the checklist as a 'heads up' as not to create confusion for the pilots; even if only momentary.