If you’re a fan of the show LOST, the you owe it to yourself to check out the LOST Easter Eggs site. They’ve got tons of pictures (screen caps) from the shows and have found tiny connections from episode to episode that I never would have noticed. Definitely a great resource for taking a close look at past episodes and it’s spoiler free.
Another great section on the site is the LOST Books page. Sawyer, and others, are often reading. The books they read are selected on purpose and often relate to theories about the show or themes being played out in the episode.
They’ve got several other blogs linked together and they form a nice, mini-site. A few others that are worth checking out are the Lost Connections, Theories, and Answers. Be careful, you could spend (waste) a lot of time reading all the posts.