The URL to add in "keyword.URL" becomes a link in this post, so right click it and choose "Copy Link Location" to copy it to the Windows clipboard. Then hit CTRL+V to paste it. Saves you having to type the whole thing.
To reset your home page, do the following.
Go to the site you want to set as your homepage.
Click the orange Firefox button and go to Options | Options | General
Make sure it says "Show My Homepage" in the first dropdown menu.
Click the button called "Use Current Pages" to set the homepage to the one you have on the screen.