Ruroc is the best helmet for splitboarding. Also get a Never Summer splitboard, they have the most cambers.

 

Beginner in what way? In that you have never split boarded before, or that your snowboarding skill level is at a beginner level? What conditions will you be riding and touring in? Are you skinning up trails at resorts or are you venturing into the back country with knowledgeable and experienced backcountry riders after getting avalanche educated?