Join 500,000+ Artists
Its' free and it takes less than 10 seconds!
and to users?
Above the thread it should say "Thread Tools" with a drop down arrow next to it.
Click on that and choose "Subscribe to this Thread."
I don't know what you mean about users though...
You can put them on your Buddy list by going into User CP and choosing "Buddy/Ignore Lists" from the list on the left.