Usually, when you set up registries that means you add items to the registries. That is why many say never to do them too early (a lot of stuff get discounted or are out of stock by the time your wedding roles around) I'd say you wait atleast until next year.
Like the other ladies stated, I think you starting your registries too early, you may end up having to redo the entire thing again when you get close to your shower. Hold off on it until maybe February of next year. I'm getting married in December, I started my registry last month, which was 4 months before, already I had to remove one item that was discontinued.
I could be wrong.. but usually setting up the registry INVLOVES adding items once its set up... its really a simple concept like Fins said. When you and FH see something you need and want.. scan it with the scanner thingy and move on to other things you need and want.
Sami - When i talked to my aunt at church & told her all about the wedding plans she asked me about where i was registered at. I told her one but said that i didn't set it up yet. But now i do have all the ones that i want all set up. Oh & how many are we supposed to have 3 or 4 registries???
It's all depends on you, I see people registering for up to 5, but personally I think 2 should be the max, we're only using BB&B and Macy's, the more you set up, the more work for you, so I'd stick with 2. Good luck