Minimum Data Required

Mim would abe the lat/long.and one field but go to the FAQ and there are some very good instructions on building a POI.

http://www.poi-factory.com/garmin-csv-file-format

From that page

The simplest files have one row of data for each location, with 3 values in each row: longitude, latitude, name

Here's an example with 2 locations:

-123.12345,34.98765,"Amy's House"
-123.12332,34.98622,"Gary's Garage"

Since you are a TomTom user, it may be different. For Garmins you only need three columns. The third column lets you choose and see what the coordinates are for.

Daniel