Garmin POI Loader
From Wildsong
You can download "POI Loader" from the Garmin site.
GPX format
CSV format
Then you can create simple CSV text files containing points in the right format, and load them into a Garmin handheld with POI loader.
Here is the format of the file, cribbed from Garmin's docs
<Lon>,<Lat>,["]<Name>[@<Alert Speed>]["],["] [comment]["] Longitude and latitude must appear in WGS84 decimal degrees format (ddd.ddddd; negative numbers indicate West and South). If you include quotes around the name or comment, you can include line breaks in the text. The following are examples of Custom POIs in the proper format: -94.81549,38.80390,Bonita -94.79731,38.81099,Ridgeview@25 -94.74240,38.81952,Heritage Park,Perfect site for a picnic -94.76416,38.81227,Garmin,"1200 E. 151st Street Olathe,KS 66062 913/397.8300"
Download POI loader and refer to its internal docs for more information.
Custom bit maps
Name the BMP file after the POI file and POI loader will use it for all points in that file, for example "restaurants.csv" and "restaurants.bmp".
Bitmaps should be 24x24 or smaller. Magenta is transparent by default.