This section provides high level things to check when preparing your data. You will likely need to do additional quality checks that are specific to your data. Please take this section as minimum things to check.
See below to help us build out more detailed guides and references for data preparation and data quality.
If merging tables from multiple sources (like counties or regions)
Check all expected fields are accounted for across data sources
Check the same number of rows exist in your merged dataset as there are in your individual tables
Check that data types are consistent within fields in your dataset. For example if the field is supposed to be an integer, confirm that it only contains integers
Save your tabular data file as a delimited file such as a comma-separated values (CSV) file
Resources on using and exporting delimited files like CSV