Carol,
Here's some info on number 1...
If you have a table containing address info for your classmates, you can batch geocode (at least 2500 records) for free using the Texas A&M geocoder service:
Texas A&M Geocoder - Free online geocoding
You'll want to save your data in a .csv format to process on TAMU. Once you get the lat/long data, you can insert into ArcMap. The output from TAMU, if I remember, is a flat file. ArcMap can work with this, but to make it easier for you, you may want to load the flat file data into Excel first. Here's a tutorial on how to both load and save flat files:
Import or export text (.txt or .csv) files - Excel
Here are some youtube tutorials on how to add your points to ArcMap:
How to make a shape file for Arcmap GIS using latitude longitude coordinates in an excel table - You...
Adding XY Data - YouTube
Importing GPS Coordinates from Excel into ArcMap - YouTube
TAMU should return lat/longs in decimal degree format, which is good. It should also correctly label lat/long, and ArcMap will pick-up on this by the "lat" and "long" column names. In the event they do not look right, try flipping them... this is a common mistake - just remember, lat = y; long = x for our purposes.
