Ethernodes.org is an interesting site that lets you view information about all of the nodes running on the Ethereum blockchain including IP address, port, country, city, client type, client version, OS, and more. You can use it to verify that your node is online or to view the details of other nodes. The easiest way to find your node is to search by your IP address (find your IP address here).
See a graph of the breakdown of all nodes by country, client, client version, and OS at:
https://www.ethernodes.org/network/1
Search for more detailed node info, including by IP, at:
https://www.ethernodes.org/network/1/nodes
You can also list your node on the colorful Ethstats.net website at:
https://ethstats.net/
Instructions for listing your node are found at:
https://github.com/ethereum/wiki/wiki/Network-Status
The above instructions aren't Windows friendly. Hopefully someone can post these directions in the future.