I always start at the beginning when anyone has a question about seeing SA or Plus.
First things first -make sure you log out of SA, then log in to Plus and stay logged in. If you go back and forth, you will pick up an SA cookie. I find it better to stay in Plus.
Next, the forums. To me, the forums look mostly the same except that in Plus, the first thread is "Sweepstakes Plus Members" which you will not see in regular SA.
The sweeps listings - In SA and SP you will have access to the same sweeps, but in Plus, you will see that there are categories for Facebook, Twitter and Blogs.
The Plus Members Only Sweepstakes - (in addition to Amy's answer) a new easy way to find this sweeps is from the Sweeps Plus Home Page, where it is listed in the column on the left:
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