When looking at your InBox - there is a blank "checkbox" on the far right side of the screen next to each message. Click it to "check" mark the messages you want to delete. Below all the messages is a pull-down menu for Selected Messages (the default is "Move to Folder..."). Change the pulldown to "Delete" and click the "GO" button. You can also click the box on the right side next to each group of messages (Today, Yesterday, Last week, etc) to mark all the messages in that group instead of clicking on them one at a time.