These updates will appear on the home screen, if you want to view individual updates simply go to the page of that user and you may see all their tweets.
No. Only people that person is following are the ones from who she gets updates. If you mention the person's username preceded by an at, your tweet will appear at the user's mentions page.
Following on Twitter simply means you're are watching for updates on a certain person's account. When two people follow each other, they can send direct messages as well.
It depends on your mobile phone plan.
Twitter is like myspace or facebook. You can follow people's updates. Say if Selena says 'Just finished picking out the picture for my album' if you are following her you can see that she wrote that. You can either reply or favorite the update or none. If someone is following you and you are following them you become friends and you can send messages to each other.
Most likely, Twitter updates are available to be viewed by people on the Twitter Home Page. It is hard to tell what Twitter will do next, as far as new features and such.
As of March 17,2011 8,202,406 people are following him on twitter
At the top right hand corner it tells you how many people you are following and how many people are following you. If you click on those that are following you, they are in order of when they started following you. So, the one at the top is your most recent follower.
I think you can follow someone on Twitter if you have 900 K people already. It should not matter how many people you are following or who is following you.
Yes, you can see how many people are following a Twitter account. All you have to do is go to the person's profile and look at the "Followers" amount.
Someone that you are following would have "retweeted" the tweet.
If the person has email notifications enabled for new followers then they will receive notification that you started following them again. They won't be notified that you unfollowed them though.
Twitter is a microblogging service that allows people to post short updates about what they are doing. Naturally, this has grown to include much more than simple status updates. Today, people use Twitter to connect with other like-minded individuals, to market their businesses, to get the word out on important events and programs and organize meetups, among many other uses.