The statement about the canard stalling first and making a canards main wing stall being hard is correct, only if your CG is correct.

A rearward CG will stall the main wing (called a deep stall). This is usually unrecoverable and has resulted in many full size fatalities.

The trouble with canards is they have not really been studied enough for the rules to be known so it's all about trial and error. Set your CG using the Area/Moment rule as Ben said (using the centre of lift as the moment). It is all trial and error from there, but be careful of that deep stall. Maybe fit a stall recovery chute is you are building something large and expensive. I plan starting a 1/3 scale LongEZ soon (built from the full size plans, with required elevator size changes etc).

I have a St Croix LongEZ (62") and the plans for the fullsize LongEZ, Vari-Eze, Vari-Viggen and Solitaire (all from Burt Rutan). I hope one day to build a full size 4 seat Aerocanard (www.aerocad.com)