In Firefox, there is a search bar in the top right corner. You can add search engines, manage them, and use that bar to search a huge number of places on the Internet.
Or, you can save yourself a bunch of time and search with ButtonAll. ButtonAll calls itself “The Internet’s Universal Remote,” and lets you search a huge number of sites from the one page. You type a word or phrase into the search bar, and then click what you want to search.
The thing I really like about it, though, is it makes searching one thing across sites really easy. Results are opened in a new tab or window, which means you can search Wikipedia, Dictionary.com, Facebook, and Google with just 4 mouse clicks, instead of going to each site and searching again. It makes searching faster and easier, without losing any of the helpfulness of the sites.
ButtonAll (here) is a great research tool, and great for anyone who searches frequently.