Your wedding website info can go on either your save-the-dates or your invitations. One line is all you really need (www.jackandjill.com, for example). Still, an insert included with your invitations inviting your guests to visit your website for more information is nice, too. Especially if you're planning to use the website for gathering RSVPs and communicating with your guests.  Your registry information is best left on your wedding website or your wedding shower invites (if you're having one). We've seen some people choose to include it on their wedding invites or save-the-dates, but that just seems kinda presumptuous. Again, maybe that's just us.