Karen, I wish I saw your question when you wrote this. Hopefully, you have had some successes with your freelance writing since you are not new to writing anymore. If you still have this question in mind, or in the event others are thinking the same please allow me to give my "two cents"' worth.
I actually have listed HubPages on my resume or, alternatively, my CV. On a resume, I described my freelance writing on HubPages in the experience section or, alternatively, in the skills section. On my CV, I listed the relevant hubs by titled under the "publications" section.
However, there are many things to consider. First and foremost, listing your experience on HubPages on your resume should be relevant to the position you are seeking. Next, consider the quality of your hubs and the totality of the work on HubPages. HubPages can be listed in the experience, skills, activities, hobbies, and interest sections of a resume. Pick the one section where it will be most valuable.
Today I posted a hub entitled "How To List HubPages on Your Resume or CV." You may find it useful.