How do I upload:

[Carantathraiel]

My sims from the game onto the sims3.com or any other downloadable site?
I have a sims child I made myself on my game, and would like to be able to share her with the world.  

[Menaceman]

If I remember correctly then when you are in CAS you need to click on the three little dots (...) in the corner of the Sim's portrait picture.
The second item on the list should be Share Sim.
Once the game tells you that the Sim has been exported then you need to open the launcher and switch to the Upload tab.
Click in the check box next to your Sim you want to upload and then click on the Upload button. Your Sim should then appear on the official site.

To put a Sim up on any other site you would need to share the .sim file from the Export folder. Put it in a .zip or .rar file or any other type of compressed file and then upload that.

If you want to upload a family already in the game then go to Edit Town and then click on their house. You should then get the option to share them from the info tab that opens.