1. To continue on your own for some more practice, start by making railings for the porch and front steps. For detailed work like this you'll want a finer snap grid. To change the setting select "Dimensions..." from the Preferences sub menu in the Layout menu. Setting the snap grid to 0.25' should be fine for now.
To make a railing set the z of the cursor to 5 feet. Use the visual cues of DesignWorkshop to line up the cursor properly and make a box as shown below. The size of the block is 5.5' east, 0.5' south, and 0.25' vertically.
Continue making similar blocks between the posts to serve as railings. Leave a gap between the posts where the stairs pass.
2. Now make a block which will serve as the railing for the stairs. It should line up with the post and the dimensions of the block are 3' east, 0.5' south, and 0.25' vertically. The location of the block is 5 feet off the ground.
Select the faces mode tool from the tool pallette. It is right above the eye tool. Select the eastern-most face of the block you just made.
Now click on the face and while holding down the Option key (the Alt key for Windows) drag the mouse downward. This pulls the selected face of the object downward, resulting in a sloping block to serve as a hand railing. Continue pulling down until the change in the vertical location of the face is -1.5' as shown in the location bar.
Duplicate the block you just made and move it over to line up with the post on the other side of the stairs.
3. There needs to be a post at the bottom of the stairs to support the railing. To do this make a block that is half-a-foot square in plan. Make the block a couple feet high, but don't drag it all the way up to the railing.
Now you will fit the post you just made to meet flush against the railing. To do this go to the Arrange menu and from the Fit sub-menu select Upward.
This makes the selected object expand upwards until it meets another object. In this case that means the post extends upwards until it meets the railing.
Now duplicate this post and move the new one to the other stair-railing.