To use them in the map chart, you'll need to convert them to ESRI Shape files. There are some online tools (such as http://www.zonums.com/online/kml2shp.php) and downloadable equivalents that look like they'll do this, although I have no idea how well.
There are also scripts available to download for ArcToolbox in ESRI ArcGis desktop, and I believe the latest versions of ArcGis server handle the format natively.