Definitely check with ALL your older relatives, plus any other relatives since they may have already done a lot of work already. Also, the sooner you can speak with them the better. I just got started with my family tree and I'm in my forties. All my grandparents are gone, and I'm starting to lose aunts and uncles, and some who are still alive are, sadly, not all there anymore. So I've lost a lot of potential information. Fortunately, some work had already been done and I've been able to match it with online information. But check with your relatives NOW. You never know when they will be gone and all their knowledge lost.