Yep, so long as you don't sign out, or clear your cookies, or change to a different user account... or another computer altogether of course, then you can just return to your site and away you go. I might not have mentioned, you need to tick that "Remember login" box on the way in.
The Control-A and Control-C key combinations are the satndard Windows ones that simply "select all" and then "copy to clipboard". If you're on a Mac, it'll be different. You need to have your cursor in the area you want to copy. You can also use the buttons in the FCK editor toolbar for that same thing. Hover over them and you'll find the right ones.
The "clipboard" is a location is system memory. It only holds one block of information at a time so make sure you don't clear it by copying something irrelevant after copying the thing you wanted. There are Windows and Office addons that provide multiple and permanent clipboards if you really get keen. I sometimes open a text or a word document and paste into that if I want to be sure I've got something copied.
In some cases, you might switch the FCK to source view and copy that instead. You can paste source into notepad, whilst you can't paste formatted.
Oh... and I should have pointed out that Control-V is the paste shortcut combo. If you look on the menu of anny Windows app including your web browser, you'll see the shortcut keys listed next to items that have them. Look on the Edit menu for the ones discussed here.
Rob