Command A = Select All
command - v
The keyboard shortcut for adding a bookmark in Safari or Firefox is Command (⌘) - D.
ctrl+i is the keyboard shortcut of the Italic button.
Default keyboard shortcut to show/hide rulers is Ctrl + R on Windows and Cmd + R on Mac computers.
alt 4
command - E
Use the keyboard shortcut "Option(alt) + Command + M." Then change the line spacing to whatever you like. Ta-da!
It will depend on what software you are using but this can usually be found in the File menu at the top of the screen. The keyboard shortcut is usually the Command (cmd) and N keys.
As long as the keyboard is a USB 2.0 keyboard, then you should be able to use a good majority of the keys. However, keyboard shortcuts cannot be used, such as Command+Q (the shortcut to quit out of a program), since PC keyboards do not have the command key. Plus, if all programs are not responding, Ctrl+Alt+Delete will not work to forcibly quit those programs, because on a Mac you would press Option/Alt+Command+tab, and the command button isn't on the PC keyboard. You can still use the PC keyboard to type with numbers and all, but there are limitations.
With the Mac's Mail application you can show the full header information for an email by selecting Message in the View menu and then Long Headers from the sub-menu. The equivalent keyboard shortcut is Shift Command H.
the command button
From the Finder's File menu select New Folder (or use the keyboard shortcut - Shift, Command, N) or right click on the Desktop and select New folder from the menu.