The always entertaining LifeHack has an interesting article about How to Survive as the Family Tech Support Guy (or Gal). Most of us with more than a passing interest in technical matters get stuck in the role of tech support for family and friends from time to time. Sometimes this can be a rewarding experience but often it can be frustrating if expectations aren't set early.
1) This probably isn't your full time job. Even if it is, who wants to work extra hours for free? Let the person seeking your help know that you have other obligations and that their problem will have to fit into your schedule. It's okay to be a bit flexible for emergencies but if you continually sacrifice your own downtime to help others, your resentment will show eventually.
2) Find and/or train a first level family tech support person so you can advance to second level support. Usually younger people are good candidates for this since they seem to inherently understand new technologies better than most oldsters. I've been lucky that my stepfather has taken on this role for me. I'm happy to take his calls because I know when he has questions, he's done a complete job of troubleshooting which means that I've got a difficult problem to deal with. I enjoy a good problem now and then. It's telling someone how to convert pictures to a different format for the 23rd time that annoys me, especially when they can do a Google search just as easily as I can.
3) Learn which people are time wasters and avoid them. Few things are more frustrating than spending some of what should be your leisure time doing research to give someone advice only to have them do the opposite because the sales clerk at the local electronics warehouse has given them a contradicting opinion. Wow, 6 months in the industry at minimum wage gives them the equivalent of all your training and/or experience, not to mention the fact that they probably get incentives for pushing whatever crappy product they've recommended. In this case, I bow out gracefully but resolve never to spend time helping that family member or friend again.