That depends on the board settings because administrators can change the settings so that you have to be registered to view posts. You also usually have to be registered to reply and start new posts but this does depend on the board settings. To register click here. It is advised that you register so you can recieve emails from the administrator.

如There is a button that says "Login" in the menu at the top, clicking this button will take you to the login page, where you can login. Here you simply input your username, and your password and the amount of times you wish to stay logged in for.

If you have forgotten your password, do not worry. Head over to the lost password section and fill in the form and your password will be emailed to you.

Again in your profile there is a place for an "Avatar" and avatar is the image under your name. Check with your Admin about the size of your avatar, it"s usually considered common courtesy to use one under 150 pixels wide.

To add a signature to your posts you have to log into your profile and insert into the signature text box the signature you wish to use. Discuz Code and HTML maybe turned off or on. This can effect what you can insert into your signature