Joria, the way I understood the set up of the new Swap Shop board is this: we post our creations under the proper child board. Then, if you want to, you can start a thread for your own creations, like I've done, as a way for people find groups of creations more easily.
The way to upload your creations is super easy I've found, and leaves out the official Sims 3 Exchange completely!
What you do is head into the child board where your creation fits, Sims, for example if you want to post a Sim. Then you create a new thread and title it according to Carl's guideline: Sim - [Name]. Then you type up a short descriptive post (following Carl's guideline for mandatory information) with pictures just like any other post on the forum. When the post is to your satisfaction (I like to preview it) don't hit "post" just yet, instead click on "Additional Options" at the bottom left of the posting text box. Then click the "Browse" button to the right of the Attach text box and find your creation inside your computer: for Windows look under C:/Users/your name/Documents/Electronic Arts/The Sims 3/Exports. Then select the .Sims3pack file you want to attach and click open. The route to the file should now be displayed in the Attach text box beneath your post. Click on "Post" and wait. It can take a while to post but it will happen.
As for patterns, I don't know as I haven't touched the Exchange in months, and I play on a Mac so no CAP for me. Maybe a PM to Carl or Pam or Metro might be necessary to clear up the patterns concern. I haven't read an official word on that front yet.
Feel free to PM me if you need more help, I'd be happy to help.