As a site administrator (when you are logged with with administrator permissions) you will see a black toolbar at the top of the website. This is a handy tool for easily navigating to the areas you may need to access for site configuration and other administrative tasks.
Clicking on the top level (e.g., Structure, Appearance, People) will take you to the administration page for that section. So you can click on the Structure button and go to a page where you can select the appropriate tool within this section, for example content types or menus.
The tool bar also has dropdown menu functionality, so you can also navigate directly by hovering over the main button and navigating directly to a subsection or even an item within that (for example to add a block by hovering over the Structure button, and then Blocks, leading to an Add block link).
Log in using your user name and password. If ever you do not have the user log in block enabled, simply enter the website address as http://websitename/user and you will get to the log in box.
If you ever forget your password, you can have a new one-time log in password emailed to you. Use it to log in and then re-set your password immediately. Note: it is very important that you are not already logged in or you will be prompted for your old password which you do not have. So when using this one-time log in do not do anything else on the site before setting your password.
To log out use the log out button in the log in block (top of the sidebar on each page) or use the Log out link in the toolbar. Alternately, go http://websitename/logout