First off, make sure you use it. Don't create an account in a professional development or in your spare time and then forget to access it and utilize it. As I have said before, Twitter is the best way to connect to professionals in your field and subject matter. Now that you have an account, learn how to use it. Below are some of the things you need to have a good understanding of before you really can grasp how to use Twitter. I suggest spending some time looking through these.
What is a Hashtag - An in-depth description. You might also be interested in a Great List of Hashtags for Education
TweetDeck - A Desktop Software to follow your Twitter feed - A MUST HAVE - How to Tweet-deck Like a Pro and Tweetdeck Tutorial on YouTube
How Do I Find People to Follow?
That is probably the second most asked question and there are several ways. First and foremost, visit Twitter 4 Teachers and find teachers in the subject matter or area that you are interested in. Read their bio and click their name so that you can visit their Twitter page and click on the "Follow" button. (Make sure you are signed in to Twitter so that you can start following them)
Another great way, is to use Tweetdeck and follow the #edchat talks on Tuesdays (12 and 7 EST). I have discovered that this is a great way to connect with other passionate educators who care about engaging in discussions related to education and many of these same professionals share amazing resources. You can also participate in deciding the #edchat topic buy voting (Link will take you to previous topics) for what is discussed. The vote is made available Sunday's and if you follow the #edchat hashtag, you will see it. You can use this same philosophy on any #hashtag that relates to your interest. Just search for the #hashtag and read the tweets and the profiles of the people who are using it.
What About My Profile?
A big mistake many new users make with their new Twitter account is not updating their settings. First thing, is upload a good picture of yourself, preferably a headshot, and one that is high quality. Second please put the city and state/country that you reside in. And FINALLY, please include a short bio about who you are, or your interest, or what you will be tweeting about. This way people will know whether they will want to follow you back. People won't follow someone who doesn't take time to provide this information.
At the same time, decide whether you want your account to be public or private. Private allows you to approve who follows you and keeps your tweets from appearing on the main twitter feed.
Another great tip is tip is to start lists so that you can organize who you follow before you start following a bunch of people. This is something insist someone would have told me in the beginning.
What Could I Possibly Tweet About?
Anything, but I would stick to topics related to education. You could always start out by just Retweeting (forwarding) a Tweet that you really liked. See what other people are Tweeting about and Reply to their tweets. Just start a discussion and before you know it, you will be a pro at understanding this new Twitter-PLN phenomenon.
It might help to also start a blog and share your thoughts about what is going on in your classroom or school and then share some of the resources you use with your students and how you used them. It would also be good to share the activities and lessons from your classroom. Even the ones that don't go as planned because you might find someone who had the same experience, or has a suggestion for improvement. Blogging is the 21st Century method of reflection.
How do I manage followers?
You will have people who start to follow you or reply to you that are often Spam. You can easily see what they are tweeting about to determine if that is the case. You will often see them tweeting the same thing over and over again. Twitter provides and option to block them and mark them as Spam. I highly recommend doing so. You might also want to look into using the service Manage Flitter for when you increase your numbers so that you can get an idea of who is active and who is not.
For more information, I created a Glog to share several resources for Building a PLN using Twitter. You can see it below.
Happy Tweeting and Good Luck!