need category #s for wp_list_bookmarks

I’ve got <?php wp_list_bookmarks('category=1'); ?> running in my sidebar but it doesn’t supply anything.

I’m guessing it’s one of two things. (1) I don’t have the category number right. I only have two categories, so I can only assume that “1” will work in the code. But how do I make sure I’ve got the numbers right?

Or (2) I’ve got the code wrong. Isn’t this the code I would use to list the links under my first category as list items?