I am going to assume that you are already all set up with a HootSuite account. 🙂
Step 1. Log into Hootsuite
Step 2. Click on Settings, then RSS/ATOM
Step 3. Click Add New Feed
Step 4. Fill out all the options for your feed and Click Save Feed
Now you can active or inactive, you can come back and edit the options at any time.
The next time you publish a article, it will automatically publish. You can added other social networks as well.