If you are job-seeking, you need to join LinkedIn, an essential job-search tool. If youre not on a job search but youre into online networking; or want to acquire new partners or clients; or otherwise want to rev up your networking activity level, you should likewise become a LinkedIn user, in my view. All that being said, there are some iron-clad rules for polite and professional use of the network. Heres my Top Ten list for LinkedIn dos and donts:

1) DO connect to your real-world friends.

Im amazed by how many LinkedIn users join up, create a profile, and immediately set to work inviting all sorts of online strangers to join their networks. Sure, its fun to browse the LinkedIn database and look up people you might want to know better.but what about your friends back in three-dimensional space? The first thing to do as a new LinkedIn user - after creating a rockin profile for yourself - is to invite your true-blue friends and former workmates to join your network. There are three steps in this process:

a) Download your Outlook address book so that LinkedIn can find your friends who are already members.

b) Use the Find Colleagues and Find Classmates functions to synch up with people you know from school and past jobs; and

c) Invite bunches of real friends who arent already LinkedIn users, to join the network - youll be helping them get connected at the same time you grow your own network.

2) DONT become an Invitation Spammer.

Its tempting to start sending connect to me invitation to every Tom, Dick and Sally you find on LinkedIn, but its bad manners. If you want to reach out to someone youve spotted who has an enticing profile, send the person a Contact request rather than an invitation to join your network. A Contact request, to use an offline networking analogy, is like an invitation for a coffee date. An invitation to Connect is like asking someone to go steady. Unless you know a person already, dont spam him or her with a want to start recommending me to people, and vice versa? invitation - its creepy.

3) DO unto others.

Its astounding that a person would send out connect-to-me invitations while proclaiming on his or her profile that no new connection invitations will be accepted. Talk about all take and no give! There are other LinkedIn users who set up a profile and make connections, and then specify on their profiles that they wont act on requests to forward (a key piece of LinkedIns value). These messages say, I want to be on this site and get its value, but I dont want to deal with other peoples requests. A modern-day Dante would design a special, uncomfortable and crowded level of Hell for these folks: no pits of fire, but perhaps a zone where all connections are dial-up, cell phones cant hold a signal and no one helps you with anything, retribution for the me-first approach to online networking that you showed in your most recent incarnation on Earth.

4) DONT make assumptions about your own irresistibility.

Connection invitations should state clearly why you expect your invitee to link up with you - for instance, because you serve on the same fund-raising committee or because your daughters are best friends in the fifth grade. With so many activities crowding a typical businesspersons schedule and so many people in the mix, its easy for people to forget how they know you. Likewise, even Contact requests should state your case as plainly as possible. A message that says May I call you? We could collaborate is not the worlds strongest pitch. People are incredibly busy - if youre job-seeking, or trolling for new clients, you may lose sight of the fact that a person needs a compelling reason to even spend ten minutes on the phone with you.

Its helpful to remember what I call the Happy Life theory of networking: when you reach out to a stranger, that person is presumably leading a happy and fulfilling life without the benefit of knowing you. Its not enough to say Ill buy you lunch! or the online equivalent of that offer; a $25 lunch (or a scintillating phone conversation with you) just might not be as hard to pass up as you believe. So lay it out there: heres what I can do for you, or heres what I need, or both.

5) DO keep your profile current.

A pox on the person who lets her LinkedIn profile languish! If you cant be bothered to keep your profile current, why should another person bother to engage with you? If I receive a Contact request, jump over to the requesters profile, and find that its details dont match whats in the requesters email message, Im already underwhelmed. Bonus: when you update your profile, you can send a one-click blast message to let your entire first-degree network know about your news. Note: please dont abuse this feature! Reserve profile-update blasts for news on the order of a job promotion, book launch or appointment to a national commission.as opposed to news items like I have started my PMP certification class.

6) DONT confuse quantity for quality.

If I were a recruiter, Id build the biggest network I could, on LinkedIn or otherwise. After all, theres zero downside to being able to view, and reach, a massive number of candidates when your job is locating talent. But for the rest of us, its easy to get the notions a big network and a strong network confused. The question to ask yourself is could I recommend this person, and could he recommend me? If not, the principal value in any individual LinkedIn connection will be your ability to view his network (and vice versa). Thats not a bad thing, but it would be a shame to mistake that kind of visibility for influence. Amassing connections can become a kind of addiction, but withdrawal will kick in when these near-strangers begin to ask you to vouch for them to your dearest friends.

7) DONT pass along questionable requests.

I got religion on this item in an instant last summer, when a fellow asked me to send a friend of mine a spammy invitation to his business conference. I cant do it, I wrote, its purely a marketing message. The gentlemans return message essentially ripped my head off, affirming my initial gut reaction that his request was an improper one. Dont hesitate to stand up for yourself and for your friends when sketchy requests come down the pike (and they will). If you pass along every bit of dreck that finds you, your trusted friends will start to doubt you, and thats a far worse fate than having to write to another LinkedIn user, Im sorry, but I dont feel comfortable passing this on.

8) DONT abuse the Find Colleagues feature.

LinkedIns Find Colleagues feature allows you to find old workmates and send unmediated connection requests to them, a boon if youve lost their email addresses over the years. Unfortunately, its easy to abuse the feature by listing false employers or dates of employment on your profile. What can we say about this? If you believe in the wheel of karma, avoid the temptation to claim employers and employment dates youre not entitled to.

9) DO join the PowerForum.

Newbie LinkedIn users have lots of questions, and a great place to get answers is the user group called MyLinkedInPowerForum. Send a blank email message to mylinkedinpowerforum-subscribe@yahoogroups.com to join the group and get LinkedIn (and general) networking advice. MLPF founder Vincent Wright is a helpful guide and mentor to LinkedIn users all over the world - I can virtually guarantee that youll learn something useful from the Forums daily conversation.

10) DO disconnect from bad apples when you need to.

Finally, its worth noting that LinkedIn gives you the ability to disconnect from other users if you find that the connection no longer works for you. If youre plagued by inappropriate requests or other annoyances from one of your connections, you can cut the cord and save yourself from recurring headaches. Some people just dont get the notion of an online community with standards and norms; and its not your job to teach them how to behave. Just move on.