Help with Use Case and User Story examples

Greetings everyone, my name is Nick and I am a computer science major working on my A.S. Degree at Glendale City College, working on transfer credits and the class I’m taking is Systems Analysis, and this is our first UML assignment, so I am a noob having just started reading O’Reilly’s UML 2.0 and I understand the notation but I’ve never done a User Story and/or Use Case Diagram before. Our assignment is to sketch up our own Use Case and User Story Diagrams of any search engine we like, so I naturally chose Google for it’s originality and simplicity… So my question is, could someone please post me a Use Case and User Story example diagram of the Google main search page and Advanced search so I can gain some insight on how to go about this, I’m sure most of you have done websites and other stuff like this before, so I confident I could learn a lot from a well-sketched example, thank for your time and I curious to see what archetypes this forum will come up with?

Just think, how would any of you guys go about this, any opinions pertaining to how it should start?