If you're registered for the LSDAS, I recommend pulling up the UTexas application. They provide a fairly long list of what they want to see on your resume -- it may be going above and beyond what all schools want, but I imagine it probably includes what every school wants individually. Throw into that mentioning the Hrs/Wk at each job/activity/organization.
Being so much older than the average applicant, I imagine (but do not know) that 1) law schools are probably going to expect a longer resume from you and 2) that volunteer activities are not so much an issue. I think volunteer/community service activities matter for college kids since, for many of us (not including me and not all, obviously), during our college years we don't have much to do besides school, so we *should* at least be carving out sometime each week to give back to the community. But I really, again, do not know and perhaps this is a question best left for the non-trad board?