I'm trying to add some point data from a csv file (it's in decimal degree lat lon) and overlay over road data that I already have added. The problem is that I can't get it to line up. I'm sure I'm making some kind of mistake with the coordinate system, but I can't figure out what it is. The data appears to the left and down miles away from my road data. When I import the same data in arcgis, I have to choose GCS_North_American_1983_HARN as my geographic coordinate system to make it line up, but that does not seem to be an option in quantum gis. Any suggestions?
GCS_North_American_1983_HARN is EPSG:4152, but that should line up with EPSG:4326 WGS 84.
What CRS have you chosen for your road data? That would be most surely in a projected CRS using metres or feet as units.
If you have activated "On-the-fly-reprojection", your data should align, if both layers have correct CRS assigned.
Please look up the extent of the two layers with rightclick, Properties, metadata tab.
If you are in doubt which layer is right, change the project CRS to EPSG:3857, and add an Openstreetmap or Google background via the Openlayers plugin.