Keep track of updates to Revit 2015 products.
If you want to follow along check you are logged in, look right, click on Thread Tools and subscribe as shown below:
2015-06-05_1245.png
As I write this the latest update is 2015.0.15 Security Fix. See Autodesk's Autodesk Revit 2015 Product Updates for more information.
Have you tried out the Autodesk desktop app? Is it helping you keep track of updates?
If you need to know what your current build (version) is, take a look at How to tie the Build number with the Revit update (thanks dkoch)