It differs a lot. Depends what i'm doing that day. If i'm just on forums all day then maybe 10-20 (mostly to use the dictionary or check spelling, okay so I should probably just get a spell checker...). If i'm working on an essay or something for uni it could be 50+
8-10 times a day on average basis, Google is best friend of all those who doesn't goes against its T.O.S
I don't count how many time i search daily but this is for sure that i need google regularly. 20-50 times daily.
I use it at least 50 - 75 times a day.. embeded in my IE and FF toolbars.. Also use google desktop as well..