I'm on Google all the time! 

With me and my terrible English skills, spelling and correct grammar usage are the top two things I commonly look up. I could take the lazy route and use a spellchecker but then I would never retain how to correctly spell things and miss the opportunity to hone in my grammar skills. 

A very close second for me would be figuring out what a certain idiom means or finding synonyms to find an exact word needed for a given phrase since words with the same or similar definition can impact a sentence in a very different way. Besides, I love learning new words! I have a whiteboard set out for new words I find so that I have a list to memorize from. 

I do spend a lot of time doing research but the first two things take up the bulk of my Google searches but definitely not my time since I have a tendency to go off on a tangent while researching and learn a lot of interesting but unneeded crap for what I am working on.