Facebook?

Follow the below link, to go to online Facebook software:
http://www.facebook.com/

Click on "Sign Up" button, to create your account.
Also do not forget to upload (some) picture that represents you, or something from your computer. This is asked when you asked to upload/give "Profile Picture" on Step 3 just after your registration is successful.

On the Top, you will find the Friends, Inbox, etc. links that you can play with.
You can view your recently added friends, all of your friends, find friends, and more.

On the Top again, you will find Profile, where by clicking you can write about yourself on the left, write your daily views, upload more photos, etc. in the middle of the page.

On the Top, thru Inbox, you can send email to some one very quickly.

On the Top-Right, click on Settings, you can edit your details, name, email, etc.

Read about of people's profile, by "Find Friends", check their profiles, if something is share publicly, also "Add as Friend" to invite friendship. You can also view their friends, also after adding a person as friend, and is approved by the person, then you will be able to view more details about it, also his daily messages, etc., online chat, and many more.