First, after an import to the original template, open the data panel. Once imported, are there any new data fields there? If not, from the data merge panel, try merging.
Also, when you go to open the data file, there is an option to show the import dialog. Is that selected? It doesn't need to be if the template and data file has been set up. So try merging to a new file. Don't be tempted to Preview the merge. It can cause problems.
I go in the data merge box and "select data source". I chose the csv file I created and nothing happens - no error message, no data fields at all. InDesign just sits there. I have gotten it to work once but it brings in all the info from my spread sheet and I just want certain info. I have tried to adjust that csv file to deleted the unwanted info, safe it and then try to open it in INDD and no luck.
The template should be showing the fields placed on the ID page. Are there placeholders in the template?
What type of SCV are you saving the data file to, and from what application?
Would you please provide screen shots of the template page showing the placeholders the merge panel showing?
Where does the CSV file come from. Here in Germany with German versions it is absolute impossible to use CSV files created on a Mac version of Excel. Other languages might be affected as well. (In German dot and comma are exchanged and MS exchanges in CSV files all commas with points which makes them unusable to use in Data Maerge.)
You could try to use tab separated txt files instead. I had never a problem with those. They work better than CSV on both sides, at least here in Germany with German versions.
Also check the import options of the data source file.
It also happened to me yesterday, that the wrong options for a Unicode (UTF-16 Little Endian) encoded CSV file were in place and nothing happened after I tried to import the CSV. I played around with the import options before to import a CSV from OpenOffice.
Note: The options you can see in my screenshot are not the appropriate ones for every CSV source!
Just an example, that is working for my kind of source where Unicode (UTF-16 Little Endian) was needed to successfully import characters like:
\u0160 LATIN CAPITAL LETTER S WITH CARON
\u017D LATIN CAPITAL LETTER Z WITH CARON