I have a shader and a camera system soon to be ready to put on the asset store.
What is the best practice to have it beta tested by some community members?
Just put up a thread? Is there a specific forum for it?
Put up a forum in the WiP section. Then when you get some interest, invite a few people to beta test. Most of the testing I have done has been through a Skype chat with testers and developers involved. Seems to work well. Every one I have helped beta test has gone on to do well on the asset store.
Not to say that is because of me. LOL Just the process has been very good.