Previous Topic 

Displays the previous help topic (if any). 

Alt + P 

Next Topic 

Displays the next help topic (if any). 

Alt + N 

Home Topic  

Displays the home (top level) topic. 

Alt + O 

Topic History... 

Displays the Help Topic History dialog box which allows you to navigate easily through the help topics you have already viewed. The uppermost topic in the scrolled list is the first topic you displayed. The bottommost topic is the last topic you have viewed in the current path. The highlighted topic is the current topic. 

Alt + I