Images will be in FITS format. Your browser should attempt to save the file to disk instead of trying to display it.
The coordinates can be in either decimal degrees or HMS/DMS format. (That's decimal degrees for the RA, not decimal hours.) If you use HMS/DMS format, the hours/degrees, minutes, and seconds should be separated by a space, and seconds must be included.
For example:
RA DEC
------------ -------------
187.277915 2.052389
12 22 31.98 29 53 45.55
If the dec is positive, then the plus sign is optional.