When young people want to socialize today, they’re as likely to go online as they are to head to the mall. Connecting virtually, they hang out at MySpace, Xanga, Facebook, and more than 200 other social-networking websites—and the number is growing daily.  Parents have heard much about the dangers. Crafting rules to effectively manage children’s use of these websites is the modern parents’ dilemma.  Here are a few basics that parents can adopt.