I am assuming that you mean 'within HubPages'? If so the Bookmark capability has recently been removed due to lack of use by members.
If you want to find Hubs that others have written go to 'explore' on the navigation bar and you will find 'Hubs' go there and you will options to locate all Hubs in a number of ways. I hope that helps you? happy Hubbing :-)
I have now started 'Bookmarking' Hubs of interest in my Browser (Firefox)