Pressing Ctrl + T will open a blank new tab or if you want to open any link in a new tab press your middle mouse button (often the scroll wheel) to open that link in a new tab.

Oops, close a tab you didn't want closed, press Ctrl + Shift + T to undo any tab close. Pressing this multiple times will undo multiple closes.

Quickly get to the URL address bar by pressing this function key.

Pressing Ctrl + F will open the find feature. Using this you can quickly find text within the same page. If you wish to do a quick find and have Firefox scroll to the text location as you type press forward slash (/) instead while in the browser.

Close the tab you're currently in.

Move between open tabs.

Open bookmark window for page currently viewing.

Pressing Ctrl + <plus symbol> will increase the font size, pressing Ctrl + <minus symbol> will decrease the font size, and if you wish to reset the font size back to the default press Ctrl + 0.

Make the screen full screen, removing all toolbars and status bars.

Open the Download Manager window.