How to project the data in feet /meter

Discussion created by adjotsa on Jun 15, 2011
Latest reply on Aug 19, 2011 by JS-esristaff
Dear all,

I am mapping the prevalence of Schistosomiasis in more than 300 villages in Mali (West African country) for my GIS class project that is due next week.  My data are unprojected (decimal degree).
Since I didn�??t have a basemap of Mali,
First, I added a shapefile of Africa that I downloaded from this website
Then, I used the �??select by attributes�?� option to create the Map of Mali. The coordinates system is label as <Undefined> in the data source,
Next, I added the Excel file to the table of contents and display the X Y data.
I exported this data as a shapefile   still in �??decimal degree�?�
When I right click the Layer, In the Data Frame Properties under coordinates System, I have this message
�??Unknown, Note: one or more layers is missing spatial reference information.  Data from these layers cannot be projected.�?�
Can someone please tell me
(1) Which Projected Coordinate System is usually used for data in Mali? I want to be able to project the data in feet or meters, not in decimal degree, because I have some further analysis to do.
(2) Where can I obtain a shapefile of Mali with administrative boundaries
(3) Where can I obtain a shapefile for Mali rivers
Thank you