There are many editing or geoprocessing options within ArcGIS. Both Raster and Vector files can be altered, however, most ediitng is done with vector files.
We are currently running ArcSDE, which keeps all of our GIS datasets in a single geodatabase. This allows all the users to access all the datasets simultanously. It also has the capacity to allow multiple users to edit the same dataset, however, since we only want to maintain a single set of datasets, it is not possible for RMBL users to edit datasets directly from the geodatabase. In order to edit a dataset, you must first export it from the geodatabase.
Open ArcCatalog > Navigate to Database Connections > Double-click GISdatasets.sde > Highlight the file of interest > Right click and choose Export > How you export depends on what you are exportin. If you are exporting a vector file, then you should select "To Shapefile (single)". If you are exporting a raster, then you should select "Raster to Different Format". You can either add a .tif or .img (to export it as a geotiff or Imagine file) tag on the end of the file name or leave it without a tag and it will export as an ESRI grid (default). Keep in mind that the metadata will not be exported with the data.
Exporting and Importing Metadata
In order to get a metadata file, you must highlight the file in the geodatabase in ArcCatalog > Click on the Metadata tab > click on the export button in the toolbar > Choose Format = FGDC CSDGM (SGML) > browse to the appropriate location > Click OK. Then, you can import the metadata into your data. To do this, navigate to the folder where you exported the dataset > Highlight the file > Click on the Metadata tab > Click on the import metadata tool > Browse to where you stored the metadata when you exported > Select Format = FGDC CSDGM (SGML).
Open ArcMap > Add in the file of interesting using the black and yellow plus sign (+) > Make sure that the Editor toolbar is open. If it is not, go to View > Toolbars > Editor. Click the Editor pull-down menu and choose 'starting editing' > Select the folder which includes the file you want to edit. > Make sure that your file is selecting in the target pullodwn. Now you can add/delete/alter points, lines, and polygons. When you are finished, click the editor pull-down menu and choose stop editing > Save edits (if you want to). Remember, once you save edits, you cannot undo. The changes are permanent.