Facebook is getting me confused
there are fanpages for website/blog
there are likes
there is share on facebook option
so on my blog what should I implement ?
on my posts should there be a “Like” button or should there be a “Share on facebook” link ?
The easiest option would be the share button. Fan pages are easily ignored by FB users, but the share button shows up much larger and more noticeable on a friend’s news feed.
You should implement the tools that people are most likely to use for your site. On a blog a like button is great for showing interest, and can integrate with a share / comment tool easily. You may also want to use Facebook connect to let people easily comment and join the discussion.
Fanpages are usual the site that businesses use to advertise their products/services. You lists all the information about your business, photos, events etc.
When someone “LIKE” your page they will just click on the like button and they will be updated with whatever you post.
Share is used if they want to recommend your page to their friends.
Try all those in Facebook so that you can familiarize yourself.
Hope this helps. 
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figuring that out is the hardest part 
You can aswel change the url in your facebook button link.
For example with a porn site…
No visitor will look to your statusbar to see what site will be linked.
If he click on like, he thinks he likes your site, but on his facebook page, a porn url will be linked.
With some javascript you can hide the statusbar url aswel
<iframe src=“http://www.facebook.com/widgets/like.php?href=[B]http://www.pr0n.com[/B]” scrolling=“no” frameborder=“0” style=“border:none; width:450px; height:80px”></iframe>
I would use both. A like button is better for more passive readers that don’t like to do much. Share button is for the bigger fans of your blog and content. Moreover, don’t forget the biggest different between the buttons, “like” can be traced while the share button does not provide information on how many people have used it.
it would be ideal to do both likes and share are the 2 of the best feature of FB