Collecting data is an important part of analysis, and an important skill of an analyst. However, sometimes we can use existing data sets, either because they already exist within our organisation, or because they are easily accessible. Working with pre-existing datasets lets us practice the other aspects of analysis, so we love the resources online where we can find published data sets. Most of them are well documented and ready to use!
Here are some good resources to find data sets online (please nominate more by leaving a comment!)