To Tweet or not to Tweet

So I have been contemplating joining Twitter recently.  I am not sure if I really need another social networking site to become involved in, but I sometimes think it may be a useful tool in life.  I mean if you use it for a specific reason in your life then maybe it won't become all consuming.


I had taken against Twitter when it first came out because Facebook was so all consuming that I just couldn't possibly spend more time on the internet updating another social networking site.  Since I have become involved with Facebook, my other social networking websites have been neglected.  I haven't deleted them, but I should since I never access them.  I love Facebook, I am definitely a fan of Facebook, but it is very time consuming, so do I need another site to consume more of my time.


I have some questions about Twitter that I feel I have to have answered before I can sign up with them if I do sign up with them and I felt this might be a site to ask those questions.
1)  What is the premise of Twitter?
2) How do you find people or how do people find you on Twitter?
3) Do you have a profile page that you input information about yourself?
4) Can you have more than one twitter account? (Not sure why I would but if I decide to use this as a teaching tool I would want a separate one from my personal life account)
5) Any other helpful hints as to why Twitter is good or why it should be avoided.

Thanks to anyone who replies!!!