This post describes how we can create our custom help for our salesforce apps
We can change the URL on “Help for this page” link with our URL by setting the value at:
Now when the user clicks on that link on any custom tab he will be redirected to our custom help URL:
And we can also make our help pages show help content based on context selected.i.e context sensitive help. We can see here that when user clicks “Help for this page” link few parameters are automatically appended by salesforce: (http://kartikunplugged.blogspot.com/?loc=help&target=co_overview.htm§ion=CustomObjects ) so that our pages can parse those and can show the help content accordingly.
So if we write logic in our help pages to extract those parameters and show content accordingly, we can develop custom help more effectively.
**Note: We cannot change the URL on “Help” link that appears on each page(Highlighted in green box in above image). That shows only salesforce help and training section.

