> - do other couples test it out like that too ?
Yes, its a great idea. The first time you are there, you should commit to only watching, chatting and potentially having sex with each-other.
> - what are the things my wife & I should discuss beforehand ?
Discuss your rules. What are you going to do? What aren't you going to do?
What are you going to do if something goes wrong?
Whats the "codeword" for when you want to pull the emergency break?
What are you going to tell other couples when they ask about you?
Are you going to use your real names?
> - It might sound silly, but what do u actually wear to a swingers club ? for females I could imagine some hot lingerie. but what about the guys ?
Anything that makes you feel good, sexy & confident.
>- any other good advice ?
This board has a pretty good handbook that you may want to check out.