To create a bookmark, all you have to do is press CTRL+K or CTRL+SHIFT on the line you want to place a bookmark and press a number from 0-9 (for example, CTRL+K 2 or CTRL+SHIFT 2). To get back to a bookmark you've created, simply press CTRL and the number of the bookmark (CTRL+2 for example).
NOTE: If above key combinations doesn't create bookmarks for you, make sure that your "Editor SpeedSetting" ("Tools | Options | Editor") is set to "Default Keymapping."