You want your students to look up information or do a little research on their own. You turn them loose and they do exactly what we do. They just Google and click on the first link they see. Sometimes they end up clicking on the ad which might lead them in a wrong direction.
Does this sound like something you have experienced?
Custom Search Engine - it is exactly like searching Google except you can limit what it searches. Searching butterflies on Google gives you millions of pages to look at. A custom search limits the results to a few websites you pick from. Creating this is pretty simple.
Custom Search Engine Creation
Start - cse.google.com
Click New search engine.
Add sites. These are the only sites your students will be able to search.
Click Public URL.
Some will email this to their students while others may paste it to a Google doc to share it that way. Either way your students have a targeted search engine that should yield amazing results.