No one can see your search history but you or any person who uses that same unit. Google keeps a lot of info on you and everybody else but they'll never use it for anything.
If you want to make sure everything is gone when you're done then download the free version of CCleaner. It cleans all history and internet cache. Just get the free version and you'll not have any more worries about it.
www.piriform.com/ccleaner
