Increasingly, information is being collected and stored digitally in huge volumes. Older archival and print media is also being digitised. If you have a research question that would best be answered by large amounts of data or text, then TDM could be for you. If you are completing a systematic review, see the Systematic Reviews page for information more specific to this process.
Text and data mining is an iterative process of inquiry and discovery; your question or perspective may change, and so might your methods.
There are some different places you might be starting from:
Do you have a research question that would be best answered by TDM methods?