In Safari. Open the bookmarks using the open book icon. Find the bookmark you want to delete. Tap on the Edit button at the top right of the menu list. Tap on the red minus that appears to the left of the bookmark.
On the Home Scree. Tap-hold on any app icon until they all start to wiggle. Tap on the X in the top left corner of the bookmark icon you want to delete.
If you have the iBooks app installed, go to the iBooks Store in the app and search for the iPad Users Guide. It's free and chock full of this kind of information. Or, you can download the PDF version on your computer here: http://manuals.info.apple.com/en_US/iPad_User_Guide.pdf