If this is compiled HTML Help (.chm), the simplest solution would probably be to use run-time merging. That is, you store the common topics in a separate .chm file and place references to it in each of the other files. The result is that, when the user opens one of these files, the contents of the common .chm file appear automatically in its TOC, index, and search results. See:
Thanks Pete. I had a look at the instructions in the link you provided, but it seems like there are a lot of steps needed to ensure all the links between the two help files are working. I found a suggestion to build the common chm file, then import these common topics into each new chm file I build. There's only about 10 common topics that I need to start each new help file with, so I'm going to try this suggestion and hopefully it works!
Try using the Snippet feature of Robohelp.
From the Robohelp Help: You can use RoboHelp to add custom HTML code snippets to a project for insertion later into desired topics. When you modify a code snippet shared by different topics, the changes are reflected in all the associated topics.
HTML code snippets are stored in a Snippet library as separate files with the .hts extension. The Snippet library provides thumbnail views of snippets in the Snippet pod. You can drag snippets to desired locations in a topic. You can also select one or multiple snippets and then copy, duplicate, or delete them.
You can learn more about the Snippet feature through Robohelp help files.
1 . Add a topic as a snippet
1. Select View > Pods > Project Manager.
2. Right-click a topic in the Project Files folder.
3. Select the Add to Snippet Library option.
4. Change the name and description of the snippet.
5. Click OK.
2 . Import snippets
HTML code snippets are stored as [filename].hts. Snippet files imported from other projects are copies of the originals, so modifications to the original files in the other project do not affect the imported files.
1. Do one of the following
§ Select File > Import > Snippet.
§ Select View > Pods > Snippet. The Snippet dialog box appears.
Click Import Snippet. The Import Snippet dialog box appears.
2. Locate the desired project folder, and select a snippet file.
3. Click Open.