Well, sure, I can do that. Just like you can teach me World History in 15 minutes... Explain calculus in 15 minutes... Give me an overview of plant DNA in 15 minutes... Unless your students are already proficient library users, familiar with when and how to use subscription databases, it will be a wasted 15 minutes.
I do my best to accomodate any and all teacher requests - even the 15 minute overview. But, naturally, I do a little educating along the way. I begin by asking questions... what is the teacher's objectives and goals? Which resources would they like spotlighted? With which resources are students already familiar? Are students currently doing research? About what? If not, when will they begin their next project? The best time to introducing resources is when the learning will be applied.
I much prefer to introduce one resource at a time when they are relevant to instruction. Then provide time for students to use them, practice, ask questions, make mistakes, and get comfortable.
My goal is to communicate that a more effective approach is a frequent 15 minutes (or full class period) several times throughout the year, introducing individual resources that apply to and enhance what is currently being taught in the classroom. It takes collaboration to make library resources an integral part of the classroom curriculum, not something you find some spare time to do.
Think of the last inservice you sat through where information you might need "someday" was thrown at you (i.e. staff handbook). Do you remember where to find that information? Do you even remember what was covered? Probably not. But if you ever have had an on-the-job injury or a possible situation involving harassment, I bet you can quote page numbers and paragraphs in the handbook.
Please, if you want to use library resources, give them the time that is due. You can't even read a newspaper in 15 minutes.