Hi bobdavcav,
Thank you for using the Apple Support Communities! I understand you want to know how to view the details about your playlist, such as the length and size, when using iTunes for Windows. I can help.
When you open iTunes on your Windows PC, you should be able to see these details under the album cover once playing the playlist. There is also a status bar you can view at the bottom of the iTunes window which shows these playlist/song details. If you do not see this status bar at the bottom, please navigate to View > Show Status Bar. The status bar should then appear at the bottom and when you tap on a playlist, the data will appear.
Here is the iTunes for Windows User Guide, which can also be handy for any future questions: iTunes User Guide for PC - Apple Support.
Best regards.