We seem to spend most of our time in Outlook working with email and that is where there is likely the most to be gained from using all the Outlook Search feature has to offer.
As a final note on Search, I wanted to mention that you can also search your Calendar, Tasks, Contacts, etc. I find I tend not to use this nearly as much as searching emails but there are occasions when I find it very handy to be able to quickly locate an event in my calendar based on someone’s name or a Category.
The Search Box is above and to the right of the calendar, contacts, etc. As with email, once you click in it, the Search Tools Search tab is displayed. The options in the Refine group change to reflect the type of Outlook item you are working with and it should be fairly easy to use.