As you've probably heard by now, professional networking is an essential skill — some might call it a "necessary evil" — that can help you further your career. The people you meet through networking can point you to your next career move, act as references for jobs you're applying for and mentor you in ways you never thought possible.

But networking itself tends to get a bad rap. It takes effort to introduce yourself to new people and the interactions can feel awkward or forced. They're the blind dates of the working world.

Fortunately, with the ubiquity of social networking and mobile technology, networking has changed significantly in recent years. Thanks to LinkedIn, Facebook, Twitter, Google+ and countless other social networking sites, it's easier than ever to connect with like-minded professionals and industry experts — many of whom you may have never met otherwise.

But much like in-person networking, online networking has its own rules of etiquette. Consider the following tips when building your network online.

Put the "pro" in profile. When you extend an invitation to connect, the person will inevitably check out your various social media profiles. Do the necessary prep work to make your social media profiles as polished and professional-looking as possible. This doesn't mean you should scrape your social media profiles of any personality whatsoever. Just make sure there's nothing on there you wouldn't want a potential boss to see.

Don't be a weirdo. Perhaps you met at a networking event and want to stay in touch. Maybe you have a connection in common or work in the same industry. Perhaps you simply admire this person's work. Whatever the reason you want to connect, be sure to introduce yourself — or re-introduce yourself, if the case may be — and include a quick sentence or two explaining why you want to connect. This may seem obvious, but you would be surprised how many people send invitations to connect without so much as a simple "Hi, my name is…" Not only is it lazy to not introduce yourself and your reason for wanting to connect, it can be borderline creepy.

Don't be generic. Copying and pasting the same tired, impersonal message into your emails or invitations to connect? You might as well not even bother. Generic messages are easy to spot and hard to forgive. They give the impression you're just mass-messaging anyone and everyone to build your network and are only looking out for yourself.

Be patient. U.S. Money writer Ritika Trikha sums up networking perfectly when she says, "Networking isn't about immediate results. It's about building mutually beneficial relationships." Be willing and able to put the time into building your relationships and building trust. What does that mean? Keep reading...

Nurture your network. Show your online connections some social media love and participate in the conversation. Start by sharing, liking or commenting on something they posted online, endorsing them for skills on LinkedIn or mentioning them in a #FollowFriday tweet, just to name a few tactics. The more you interact with them online, the more likely they are to reciprocate. Not only will this increase your visibility — not to mention up your social media street cred — but it will also help build a rapport and develop relationships with others outside of social media.

Try to connect IRL. Connecting online is great, but nothing beats meeting face to face when it comes to growing your relationship. If there's someone you've connected with online whom you want to get to know better, suggest going to coffee, lunch or meeting up for happy hour — and be sure to cover the bill.

Know when to move on. If someone is unresponsive, it's okay to follow up once or twice, but don't hassle the person. No one owes you anything, and trying to pester someone into connecting with you will only get you blocked. Move on to the next person who might be more responsive.

Pay it forward. Take advantage of opportunities to help others, unprompted. Is there a job at your company you know someone would be perfect for? Reach out to them and offer to be a reference. Helping others isn't just good karma, it can also pay off later if you ever need a favor of them.