STEP 1: Click What's on your mind? on the Timeline or at the top of News Feed.
STEP 2: Write status and you can choose:
STEP 3: You can choose who can see your post: Public, Friends or Only Me.
STEP 4: Click Post.
STEP 1: To post in a group, you need go to this group and click the box Write Post.
STEP 2: Write post and you can add more:
If you like you can include your location and tag others members of group in your post.
STEP 3: Click Post.
Note: All members in a group get notification about all new post in a group unless they choose adjust notification in their group. If group privacy is set to Close or Secret, only group members can see things that get post in the group.