By trying to find something in help pages, I have seen that some links could be added to make those pages more useful at finding information.
Help:Forum to comments formatting
There is no mention on the help page about forums (Help:Forum) about any of the formatting tips to help the integration of internal links or other things in comments.
The only help page I have seen talking about formatting is the Help:Wiki. So I think we should add to Help:Forum a sentence such as :
Forum's comments are posted using the same text formatting than Wiki pages. For more info about formatting, see Help:Wiki.
Links from Help:Tags to more list of tags
The help page about tags give some information about tags and talks more about categories, but the given list of tags is very small (mostly about categories) and there is no links to more exhaustive lists of tags to consider to add.
The Tags:Listing page is useless in regards of important tags. But there is a help page about that : Help:Tagging Checklist. So we should put a link to that page from Help:Tags for people who were searching for useful tag lists.
Linking "Help:Tagging Checklist" to groups of tags
"Help:Tagging Checklist" doesn't not link to any group of tags. Those pages could be useful to see what tags are available in a theme, for example tag group:background.
It could link to tag group:index which is listing groups of tags in an organized way.