Where can you find the "Detailed" documentation of the different Nodes that are available?
Here is an example: I'm using this "msg.result.push" property (because someone suggested it to me) but I can't find any documentation on the different propertys that might be available for the different nodes.
4 places to look (5 if you include the examples as jbudd points out):
Firstly in the help panel after selecting an instance of the node you are interested in.
As jbudd points out, the node's readme file should contain all of the essential information and pointers to more documentation if available. That readme comes from the source package - usually but not exclusively on GitHub.
Some more complex nodes may include a built-in help site. uibuilder does this for example.
On the GitHub/GitLab page for the node, there may be a WIKI or even something like a GitHub pages site. For example, the same documentation available in node-red for uibuilder is available at https://totallyinformation.github.io/node-red-contrib-uibuilder as well and there is further information in the wiki at https://github.com/TotallyInformation/node-red-contrib-uibuilder/wiki.