Your invitations are the first impression guests get about your wedding, so take time to get it right. Look at sites selling invitations online and in magazines such as Wedding Ideas as they can provide inspiration. You will soon learn what you do and don't like.
AT_HOME PRINTING: By far the most accessible, this is easiest option for tackling the project in smaller chunks on weeknights rather than spending hours in a studio or waiting at a print shop. However, you should test paper before buying a ton of it, printers can be especially finicky, and your can't exactly change the ink your printer uses. If your printer isn't higher end, you may have very limited paper options. Here's a little more on at_home printing.