Graphic organizers, games and worksheets are some good activities related to reading for teaching cause and effect. Examples of games include Bad, Bad Day and What's the Cause.
Students can use graphic organizers to sort out the cause and effect relationship in a book. Examples of such organizers include one cause with one effect, one cause with three effects and two causes with one effect. Students can also keep their own reader's notebooks of causes and effects they find in their books.
One way to pre-teach the concept of cause and effect is to have students play a game called Bad, Bad Day. Students take turns telling each other about a bad day they had -- they can also make it up. The other students then come up with the causes of all the bad actions that happened to the child. They then apply that logic to a story.
Another game related to cause and effect is What's the Cause. Students pull out slips of paper with phrases such as "getting wet," "spilling a glass of milk" and "breaking an arm." First they work with a partner to brainstorm causes. Next, they go around the room trying to find a possible cause for their phrase, such as "spilling a glass of milk" leads to "getting wet."
K12Reader.com also has several worksheets for teaching cause and effect in reading.