FrontierVille," also called "The Pioneer Trail," is a game application on Facebook in which you create a homestead from scratch. Harvest crops and build a home, and connect with other Facebook friends who play the game. When you "Like" the application on Facebook, you are able to see new updates and other important notifications posted by the developer right on your homepage news feed.
Instructions:
1) Log in to your Facebook account and click the "FrontierVille" link in the "Apps" section of your homepage, located in the left column of the screen. If you don't see the link, click on the "More" link and then click on "FrontierVille." The "More" link is only visible when you are hovering over one of the items in the "Apps" list.
2) Scroll down to the bottom of the "FrontierVille" game after it opens and click the blue "Like FrontierVille" link.
3) Click the gray "Like" icon at the top of the application's canvas page.
Tips & Warnings
You can go directly to the "FrontierVille" canvas page by typing the name of the application into the search engine at the very top of your Facebook screen and clicking on its name in your results.
Source: eHow
