Google Sheets - Referencing cells across different worksheets

I'm looking for assistance in creating a Google Sheet that pulls cell data (text) from one Google sheet into another Google Sheet. Based on the amount of data, and flexibility for future sheets, I don't want to use direct cell-to-cell/worksheet-to-worksheet references. Instead, I'd like to type in a cell reference into the 'import sheet' and have the data pulled from the 'data sheet' based on that cell reference. In addition, having reference cells auto-populate in the 'import sheet' will save even more time and allow future sheets to be created very efficiently.