You might find it helpful to use a dedicated COM browser. For instance, you can use the COM browser bundled with win32com to investigate available type libraries and their interfaces:

from win32com.client import combrowse
combrowse.main()

For information on how to go from the type library CLSID to the ProgID needed when dispatching, see this question.

Some citations:

As we discussed previously, automation objects are COM objects that expose methods and properties using the IDispatch interface. So how do we use these objects from Python? The win32com.client package contains a number of modules to provide access to automation objects. This package supports both late and early bindings, as we will discuss.

To use an IDispatch-based COM object, use the method win32com.client.Dispatch(). This method takes as its first parameter the ProgID or CLSID of the object you wish to create. If you read the documentation for Microsoft Excel, you'll find the ProgID for Excel is Excel.Application, so to create an object that interfaces to Excel, use the following code:

import win32com.client
xl = win32com.client.Dispatch("Excel.Application")

(from this)

The WScript.Shell object provides functions to read system information and environment variables, work with the registry and manage shortcuts. (from: 1 2)

One way to check the attributes in a COM object is using the combrowse.py available on win32com\client in your python site-packages folder

Just run the script (double clicking or from command line/python) and a window should appear with all the available com objects. Under Registered Type Libraries you should find the Shell under the correspondent Library in Microsoft Shell Controls And Automation
You can check this with the following command in python:

from win32com.client import gencache
shell = gencache.EnsureDispatch('Shell.Application')
print shell

Also, using the gencache method, you can use Tab to check some of the available methods, but for a comprehensive list check the combrowse.py. The only issue is that some of the methods listed at the combrowse.py are not really available within python.

I do not think it is possible to get the list of COM objects directly from python, however you can run the following code (and indeed run it from inside python) in Powershell:

Get-ChildItem HKLM:\Software\Classes -ErrorAction SilentlyContinue | Where-Object {
   $_.PSChildName -match '^\w+\.\w+$' -and (Test-Path -Path "$($_.PSPath)\CLSID")
} | Select-Object -ExpandProperty PSChildName

This will output a list of all valid names of COM objects on your system sorted alphabetically, and the syntax is normally MainProgram.SubFunction.

Some of the output on my machine:

I hope this helps!