Temporary Internet Files
These are fairly simple to remove. Open Internet Explorer, then go to Tools - Internet Options. In the General tab, click on Delete under Browsing History. When the Delete Browsing History window pops up, choose exactly what you want to delete (primarily Temporary Internet Files and Cookies).
If you're using the Firefox browser, click on the Firefox button (upper left) and choose Options. In the Options window, click Advanced, then choose the Network tab. Click the Clear Now button under Offline Storage.
Finally, if you're using Chrome, click the Settings icon (three lines in upper right) and choose Settings. Then click History on the left. Click the "Clear all browsing data" button and choose exactly what you want to delete ("Empty the cache" and "Delete cookies and other site and plug-in data" are the main items you are looking for).