Doing my undergrad and PhD at an average large state school, I was really lucky to get an internship (and now job), essentially by word of mouth and my PhD advisor.
Now that I'm doing a part-time Masters at an elite-ish (top 10) school, I'm realizing how amazing career services can be. They send out weekly emails saying:
"James Dimon is coming to speak." "Dir. of Engineering from Exxon will be taking questions." "Bring your resume and chat with recruiters." "Women's Society will be hosting Barclays tonight."
My state school had nothing. All of the leg work was done by individual students.