How can I make my facebook page so you have to like it to see the information?

[Logical Reasoning]

1.) To get started you'll need a "custom tab or iframe tab."
2.)Then that tab will need to be set as the "default landing tab."
3.)Then when you create the website or content that will be aggregated into that tab, you will need to implement some FBML. Wrap the content that you want to be hidden from non-fans in the <fb:visible-to-connection> tags.

The web page being aggregated into tab will need to XFBML enabled and have the Facebook JavaScript SDK.

To learn how to set up Custom Tabs:
http://www.likerecord.com/tutorial/fanpage-custom-tabs

To learn how to define the Default Landing Tab:
http://www.likerecord.com/tutorial/chang...anding-tab

To learn about setting up websites with XFBML and other Facebook Development tools go here:
http://developers.facebook.com/docs/guides/web/

Hope this helps - Good Luck!