How to get the list ID and Content type ID in sharePoint 2010

To get the List ID:

1. Navigate to list settings and copy List={ENCODED GUID}
   
   In my case it was this List=%7B2E5002B0-EDC3-4541-A0ED-2A81797B459C%7D
2.  Decode the GUID here or here
3. It should return a value similar to this: List={2E5002B0-EDC3-4541-A0ED-2A81797B459C}

That's it :)

To get the Content type ID currently associated with a list or library:

(Assuming allow management of content types is set to Yes (Under list settings > advanced settings))

1. Navigate to list/library settings
2. Under content types > select the content type
3. From the URL copy this part:
   ctype=0x0100801F054C4E00C243A9A49EC13FF778D7003293EF8DE37E144BAA8A5296D5E6CA8B
4. This the Content type ID