I am using ArcGIS 10.2, it has been a while since I did GIS. How do I calculate the distance between several points to the nearest line (trying to figure out the distance to water from several archaeological site points - I need to know how close each site is to a river, stream, lake). I did it 5 years ago using a proximity analysis but I can't remember how to do it and I don't have how I did it written down. I have a 2 meter lidar dem, a site points layer, a stream layer.
It sounds like maybe you are looking for the Near tool? http://resources.arcgis.com/en/help/main/10.2/index.html#/Near/00080000001q000000/
You do need to have the Advanced license to run this.
EDIT: If you don't have the Advanced license, check out the Spatial Join tool: http://resources.arcgis.com/en/help/main/10.2/index.html#/Spatial_Join/00080000000q000000/
pick CLOSEST for the match option, join site points to stream/lake/river. This tool runs at all license levels. Bonus, you don't even have to join the points to the line layer to get the attributes like you would have to if using the NEAR tool. This tool appends all the attributes of the join feature class (streams) to your target (site points).
You could have a look at the GRASS Tool "v.distance", its for free, therefore there should be no licensing problems, and it should do what you need. If you've never heard of GRASS have a look at this Website: http://grass.osgeo.org/
You can try Xtools Pro (http://www.xtoolspro.com/tools.asp) "Near" tool. Advanced ArcGIS license is not required to use it.