Courtesy. Treat others with kindness and respect and they will likely return the favor. This includes common courtesies like calling well in advance if you cannot make a scheduled date or party, being polite when communicating in person, over the phone, or via the internet, not making negative comments about others, etc.
Communication. Take the time to discuss your rules and limitations with your partner. You should both have a clear expectation of what activities are and are not permissible. Whatever you decide, do not break or change your rules in the middle of a date unless you have adequate time to discuss things with your significant other. If you feel your rules are too limiting, take the time to make new rules.
The right to say no. Everyone has the right to say no to anything at any time. Being a swinger does not automatically mean that you are up for anything at any time with anyone (though it is perfectly fine if you are). The right to say no includes saying no to people watching as well as touching and anything else.
Zero Pressure. Along with the right to say no, is the right to not be pressured into making or changing your mind. You should not be pressured by or pressure anyone (including your significant other) in any way. Most people avoid couples that don't seem to be on the same page. If you get pegged as a pushy couple, or as a couple where one person is “just doing it to make their mate happy” you may find it very difficult to find playmates in the future.
Cleanliness. Good hygiene is of course a must for both safety and aesthetics. Grooming preferences are just that, preferences, but be aware that many people prefer their partners neat and trimmed.
Safety. Condoms are the norm in most swinger settings, though some people still prefer not to use them. Additional protection methods like dental dams are acceptable, though not as common as condoms. Do not engage in any sexual activity that you feel is unsafe. It is your right, and your responsibility, to say no to anything that makes you feel uncomfortable.
Drug Use. The general consensus is that drugs impair judgment and performance and are frowned upon by the community at large. Alcohol is used socially by some, but not all swingers, but being drunk is also discouraged. Besides, isn't this something you'd like to remember?
Dealing with Rejection. Not everyone you are attracted to will be attracted to you. For some swingers, both members of the couple must be attracted to the couple. If you and your partner feel the same way, it may take a little time to find a couple that is as interested in you as you are to them. In the meantime, accept the nos graciously and never press for an explanation. Asking “why not” is considered pushy.
House rules. Parties and premise clubs often have house rules – like who you can bring where, what appropriate attire is, acceptable behaviors, etc. Learn the rules before you go and follow these rules once you get there.