My parents use Linux for daily browsing and general computer usage. My dad is pretty computer savvy but all his experience is with DPS and Windows. Since I convinced them to switch, they haven't needed to learn much about Linux to use ubuntu & debian on a daily basis (for almost 10 years now.) My mom knows virtually nothing about computer internals but she's at least been a desktop computer user since the days of DOS. I rarely get support calls from them about Linux problems. It's solid and reliable.