How to create and project a Point shapefile from XY coordinates using from dbf or Excel files

Creating shape file from points in GIS

1. use Excel 2003 or earlier to create a dbf III file .dbf format
2. Keep one sheet only. remove all the remaining sheets
3. give labels in first row for longitudes and Latitudes in first two columns 
4. Type  data  in two columns X and Y  in decimal degrees
5. save file as dbfIII format as filename.dbf
6. open filename.dbf file in Arcmap
7. Display XY data in arcmap by right clicling on the file 
8. select label for X for longitudes and Y for Latitudes field
9. give only geographic coordinate systems of the points
10. Project the file using project tools located in data management and feature project tools in arcgis 9.3 
11. export the projected file 

To Use directly Excel file  see the reference below


Follow the below instructions to turn an Excel file containing latitude/longitude

coordinates into a Shapefile using ArcMap.



Open ArcMap.

1. Add your Excel worksheet (97-2003 or 2007) to ArcMap 9.3 just as you would spatial data,
2. Filename.xls(x) will appear in the table of contents (TOC). Right-click on the worksheet
3. name in the TOC, and choose "Display XY Data..."
4. In the dialog box, the X Field should be Longitude and the Y Field should be Latitude.
5. If you know the spatial reference of the input coordinates, click the "Edit..." button and
6. select it.
7. For example, if your coordinates are based on a WGS84 Geographic Coordinate System, Click
8. the "Edit..." button, then the "Select..." button, Geographic Coordinate Systems 
9. If you do not select a spatial reference, the shapefile will have an Unknown Coordinate System.
10. Click OK.
11. The coordinates should plot as a point event theme. Note that it is not a shapefile, just an event theme. To create a shapefile from the event theme, right-click the layer in the TOC and select Data and  Export Data... Then select a location for the new shapefile, name it and click OK.
12. TIP: Make sure that coordinates South of the Equator and West of the Prime Meridian arenegative, or your points will plot in the wrong hemisphere!

Reference

http://www.lib.unc.edu/reference/gis/faq/xy.html