Navigation:
Turn off Safari's image cache: When you browse the Internet, Safari creates two images of the contents of each webpage viewed (a JPEG and another PNG). These images are used as seen when viewing the Top Sites or History. You can use this option to turn on or turn off the creation of these images.
Search option by default: With OS X Mavericks, search by keywords in a webpage is, by default, on the beginning of words (Starts with). You can use this menu to change the default behavior by doing research anywhere in a page (Contains).