Disclaimer: Buffy the Vampire Slayer belongs to Joss Whedon and Supernatural belongs to Eric Kripke
Spoilers: Pre-Supernatural series and eventually, season 5 of Buffy
Never let it be said that Sam Winchester didn't have connections. That would be lying, actually, so never let it be said that Sam Winchester didn't know how to use his father's connections without his father finding out because of his "puppy dog eyes and little boy sighs" as Dean once said long ago.
When he wanted to go to college and get away from the hunt, his dad was less than thrilled. Dean was no better, but he let him go without a fight. John Winchester was big on family, especially with their lifestyle. Problem was, all his uncles and aunts didn't like their lifestyle. No, they didn't know the truth behind Mary's death and John never told them, but they knew he uprooted his sons and constantly moved around the country.
Sam never got to know them and it was constantly drilled into him that they would never understand, so they were never to be told. What Sam didn't realize was the family he was to never tell was only on his dad's side. And his dad never talked about their mother beyond how he felt about her and why they needed to keep hunting for the thing that killed her.
Sam was unaware that his mom had a younger sister until one day he got in touch with one of his dad's friends during a boring day in his dorm room. He didn't know why he did it because he made it clear to his dad and Dean that he wanted nothing to do with hunting anymore. When he called, he asked how his family doing and was relieved to hear they were still alive.
He started asking about his mom, because he wanted to know more about her. He didn't have a single memory about her and he just wanted to know from someone outside the family how she was when she was alive. The contact didn't know much, but it was enough to make Sam smile and he kept listening. The contact was the one who let him know about the family that his dad never talked about. And that started something that Sam soon became obsessed with until he found what he needed to find.
He had an aunt named Joyce Summers and she had two daughters, Buffy and Dawn. His dad's contact could only tell him that much because that was all he knew. Apparently, after Mary's death, John and his mom's family were at odds over his new lifestyle and they had a falling out. He left them alone and they left him alone.
In the week of calling his dad's contact and finding out as much as he could about his aunt and his cousins through him and whatever he could find on the Internet, Sam discovered they lived in Sunnydale, California. It was quite a distance from where he was, about six hours, but that wasn't the main reason that was stopping him.
He was nervous. He had their phone number, but was too scared to call. And he couldn't just show up out of the blue announcing that he was Mary's son. He decided to wait until the second semester of his first year was coming to close. A little bit before he would need to study for final exams, though. He was just getting settled into the second semester, so now really wouldn't be a good time, he reasoned.
I think everyone can take a guess what's about to happen. It's January 2001 for those wondering, and that's your hint for what the next chapter will bring.